Christian Pulisic is still in the phase in his career when each year is the Biggest Of His Life, and 2020 is looking no different.

Having successfully navigated his initial foray into the Premier League, the U.S. international is now facing the challenge of achieving even more consistency with club side Chelsea, even as manager Frank Lampard begins bringing in reinforcements in January.

Stateside, there's no shortage of challenges, either. While the inaugural CONCACAF Nations League concludes in June, World Cup qualifying -- set to begin in September -- looms over everything. The failure to qualify for the 2018 World Cup is still casting a shadow over the U.S. men's program and Pulisic knows, more than anyone else, that the U.S. has a score to settle within the region.

Pulisic is making the media rounds after being named a brand ambassador for Chipotle (his commute to the nearest franchise is now 30 minutes, considerably shorter than it was in Germany). But as ESPN found out while sitting down with the American, he remains focused on all manner of challenges for both club and country.

ESPN: What are your thoughts on what 2020 has in store for the U.S. men's national team?

CP: I'm really excited for it. You know, this Nations League is a cool, new thing now that we can go and have a nice competition that we can play in. We're going to go, and we're gonna try to win it. And with qualifying just around the corner, I'm really excited to get right into that, and I want to secure our spot and, you know, just do the best that we can.

How tough has Gregg Berhalter's system been to absorb?

[Berhalter] definitely has an idea in mind of how he wants us to play, and I think he hasn't been able to see what exactly that is. Obviously, there's been times where it doesn't come off perfectly. We have games where we struggled or couldn't get results. But I think it's a process, and I think you can also see moments where you say, "Wow, they played really well, and there were really good moments there." I think with time, it's really gonna pay off, and I think you guys are going to continue to see that this year.

Should the team play out of the back or be more pragmatic?

We've tried to play out of the back a lot. And I think it's a really good style. But I think definitely even the best teams in the world that play that style have moments when there are times to go long. So of course, you want to find a balance, but you know, we want to be a team that has the ball a lot because it really is tough on other teams.

How would you rate the team's progress?

CP: I'm happy with it. I mean, you know, moving on out of that group in the Nations League, I think we've done our job. I think we've had some good performances. The Gold Cup, there was a lot of positives that we took out of it. So I think I'm happy with it. Like I said, I'm really looking forward to these Nations League games. We want to go, and we want to win, and we want to go into qualifying very confident and take care of business.

How would you describe the first six months at Chelsea?

You know, everyone says I'm going to go into the Premier League, it's a big change, it's tough. It's a league where there's definitely a lot of games, a lot of stuff going on, and it wasn't easy for me at the beginning, of course. I think I'm really proud of how I pushed through things and then I got my opportunity, and I felt I was playing very well recently, and I'm proud. It's been great. I've been enjoying it so much. You know, the football culture here is amazing, and I'm really happy, and I'm so excited to finish off the season strong.

What, if any, surprises have there been?

I just think the wear it has on your body. I think the biggest thing I've learned is just making sure that you keep your body right, and you gotta really work on that because there's so many games. There's a lot of stuff involved. You've got to make sure that you're healthy and ready to go all the time.

I remember talking to Landon Donovan about the Premier League, and he said it was physical in a way that was impossible for someone on the outside to appreciate. Did that surprise you at all?

Physically, I don't think it's anything crazy. It definitely is a tough league. There's a lot of games, and it is physical at times, but I don't think it's impossible. But like I said, I'm doing my best, and I know I'm trying to get used to it and make sure that my body is ready for every game.

Is there anything specific that you tweaked in your regimen to try to make sure that happens?

Nothing super-specific. I think it's just going that extra mile for regeneration after games, doing the right things, eating right and just making sure that you're ready to go.

What has been the biggest difference between Dortmund and Chelsea?

I think just the soccer culture here is what I've noticed. It means so much to these people, just in the country in general, just how your team is doing, so I think that's probably the biggest thing I've noticed. Not to say that's the case in Dortmund because that was some of the most passionate fans I've ever seen, but just the culture of the whole country, what this game means even around the holidays. Everyone's always talking about football. That's definitely impressive.

You mentioned the holidays, and obviously the games come quickly during that time. Did the intensity and rapidity of games during that period surprise you at all?

Obviously, it's my first time kind of experiencing it, but it's to be expected. People have told me and people say, "Be ready." So I was expecting it. It was nothing that threw me off.

Do you feel more famous in London? Do you get recognized more than in Germany?

People will recognize me. I play for Chelsea. Like I said, so many people watch it over here. And now I definitely get recognized walking around the city at times, but I'm not one to go walking around all the time. So I don't know about feeling famous, but yeah, there's definitely a lot of people that recognize me.

What has the process of adapting to the Premier League been like, especially when you were struggling in September?

I've just been trying to learn every day, man. I mean, I'm still learning. It's my first season now, kind of halfway through, so I'm just kind of learning to take it day by day, game by game and just focusing on the next opponent and just getting ready and healthy for the next game because it's always right around the corner. It's just a lot of competition, I think, in every game, within your team, and for every game, it's just been great learning from some of my teammates. And yeah, just being here in London, I'm just kind of taking it all in.

Are there any teammates in particular who helped you navigate through things?

So many of them, guys like [Cesar] Azpilicueta, Jorginho. They're really good guys who have been here, and they've helped me out and talked me through things. It's nice to have some experienced players to help you.

You had a period when you were out of the lineup. You did at Dortmund, too, but how difficult was it to go through that at your new club and manage the expectations for this season?

I didn't expect to come here right away and have everything be perfect and come straight in and, you know, score 10 goals in my first game. I came in, and I wanted to do that right away -- of course, everyone does. But I came in, and it was realistic, and I wanted to continue to earn my position. The beginning, it wasn't always easy, and I wasn't always in the lineup, but I just kept working. I put my head down, and I just kept telling myself, "My time will come." When you do that, and you just keep working, it does [happen]. I was really happy with kind of how things went.

How gratifying was it to push through that period?

I mean, it was amazing. You can imagine that feeling of not relief, but all the hard work paying off, and everything that's led up to that moment. Like you said, not being [in] a lineup, coming in and getting an opportunity and then getting to score three goals in the Premier League, and it's just kind of a dream come true. So, yeah, I just want to have more moments like that.

You scored some goals with your head, which I don't think I'd seen you do before. Is that something you're working on, or is that something that just happened?

I think I've always had decent timing when it comes to heading, but it's not something I specifically worked on. It's not one of my strengths, but we always worked on finishing, and when it comes to your head, that's what you practice. I don't know if I'd say it's random, but it's something that I'm just going to continue to work on here and there, and it will be nice to score on some headers.

What has it been like playing under Frank Lampard at Chelsea, and what's the best piece of advice he's given you?

Him being a former player, I've watched him a lot and obviously respected him so much as a player. Now to have him as a manager has been good, and I've just been taking it all in and learning, kind of seeing what he has and what he offers to this team. It's been fun to work with a lot of these young players as well. So I think it's been a really good mix. He's told me to just keep enjoying it and be myself.

Lampard mentioned that you had a hip/groin injury. What's the prognosis on that, and how are you progressing?

It's been almost a week, and I'm just kind of taking it day by day. I'm just rehabbing every day. I'm doing my best to be back in the next week, the next couple weeks. I don't think it should be too long, so I'm just working every day, doing everything I can to be back on the pitch.

Lampard has made no secret that he plans to bring in reinforcements [in January] now that their transfer ban has lifted. What are your thoughts on that?

It's normal. That's what happens in teams. The transfer window, players might leave, players can come in. You just work with the team that you've got, and there's always going to be competition, so you're just ready.