On May 5, one year after he went into surgery for a gruesome knee injury that nearly put an end to his Major League Baseball dreams, KBO star Sung-Bum Na stepped to the plate and gathered his thoughts.

Those thoughts initially had little to do with the opposing pitcher. Na realized the day marked the one-year anniversary of his career-saving surgery. He recalled being placed on a stretcher and eventually driven off the field in an ambulance, wondering if he would ever play baseball again.

"My injury was really serious, so coming back on the field felt kind of weird. I was thinking about all of last year, all the hard work I had done in rehab to get to that point," Na said during a phone interview with ESPN. "I thought of everything that happened, but I wasn't nervous. It was fun to be back. Opening Day was exactly one year from my knee surgery. May 5, 2019, was the day of my surgery. And I thought about that, and about how much fun it was to be finally back on the field."

On Tuesday, May 5, the KBO became one of the world's first professional sports leagues to start its 2020 season, after a five-week delay caused by the coronavirus pandemic.

The Opening Day slate of games in South Korea included a matchup between the NC Dinos and Samsung Lions. Batting third for the Dinos, Na opened up scoring in the fourth inning with a colossal home run off lefty Jung-Hyun Baek. Na, batting as a left-handed designated hitter, pulled the shot over the right-field foul pole.

Na ended up going 2-for-3 in the Dinos' 4-0 win, showing why he was super-agent Scott Boras' only KBO signing at the end of the 2019 season.

Because of the knee injury, a shift to playing baseball in the U.S. had to wait. Na, however, isn't willing to give up on his MLB dreams.

"After the injury, my perspective has not been different. It really didn't change anything in terms of the mental aspect of the game," Na explained. "I know I'm always going to work hard. I'm always going to play baseball as hard as I can on the field, with a lot of passion. And while my body may still not at be at 100% when compared to before the injury, I will get there. My mind and focus will never change. I will always believe in myself."

Na, a 30-year-old outfielder and DH, hopes to follow in the footsteps of his role model, Shin-Soo Choo. Choo left South Korea at 18, joining the Seattle Mariners organization in 2001. Choo became the first Korean-born position player to make an MLB All-Star team, and he is in the last season of a seven-year, $130 million deal with the Texas Rangers.

"I was drafted as a pitcher and then changed to a hitter. My inspiration will always be Shin-Soo Choo," Na said. "Korean pitchers have made good adjustments in the United States, but Korean hitters haven't been able to make those adjustments. Choo had a lot of success as a hitter, so he inspired me to think about playing in the majors."

Na's major league dream is relatively recent. When he was growing up in Gwangju, he loved baseball and rooting for his hometown Haitai Tigers (now the Kia Tigers), but he aspired to be a scientist. Na said he became more serious about playing baseball when he got to the fourth grade and focused on his development as a pitcher, though he never lost sight of his power, going on to become the best-hitting pitcher in the South Korean collegiate baseball league.

Na's allegiance to the Tigers ended in 2012, when the Dinos drafted him in the second round and switched him to the outfield because of his strong arm and natural ability at the plate. The Dinos made their KBO debut in 2013 and had swift success, making the playoffs in five of their first seven seasons.

Providing power and speed from the outfield for the Dinos' lineup, Na recorded at least 20 home runs and 90 RBIs in five consecutive seasons, reaching double figures in steals in five of his first six years with the team. Na's breakout year was 2014, when he became the first Dinos player to receive the league's Gold Glove award, which in the KBO recognizes excellence on both sides of the ball.

After the first of his two consecutive Gold Gloves, MLB talent evaluators became much more noticeable in their scouting of Na, particularly when training in Tucson, Arizona, the spring home of the Dinos.

"I never really thought about a move to play Major League Baseball until a lot of media started asking me about it, and a lot of major league teams started talking about it and showing interest in me," Na said. "I do think I'm a five-tool player, and maybe one day I can be like Christian Yelich or Bryce Harper. All I want to show is how hard I like to work, on and off the field. If there is one thing that I don't like are lazy plays. I'm always going to work as hard as I can on the field to fulfill my dreams. And watching MLB on TV made me have bigger dreams."

Including his 2019 injury-shortened season, when he was limited to 23 games, Na slashed .314/.381/.533 with 141 home runs in his first seven years with the Dinos. If he hadn't suffered his season-ending knee injury last year, he'd likely already be signed to an MLB contract.

While he would no doubt welcome an offer from any major league team if he is posted at the end of the current KBO season, Na has grown fond of two clubs in particular -- the Milwaukee Brewers and Toronto Blue Jays.

Rogers Centre in Toronto was the first major league stadium Na saw in person. On a visit to Toronto in 2016, he walked along Blue Jays Way and gaped at the architectural marvel, flanked by the CN Tower.

His reasons for loving the Brewers are quite simple: Eric Thames and Yelich.

Thames was Na's teammate for an extraordinary three-season stint with the Dinos (2014 to 2016). Thames was named the league's MVP after posting an impressive slash line of .381/.503/.790 with 47 home runs, 42 doubles, 140 RBIs and 40 stolen bases in 2016. He then joined the Brewers for three seasons.

And even though Choo will always be Na's favorite player, Yelich is a close runner-up.

"I watched [Yelich] during his 2018 MVP season, and I started looking up his swing," said Na, who explained he studied Yelich's swing by watching online videos. "His swing was very smooth and succinct. I would really like to have his swing mechanism."

Training in Arizona the past seven years, and spending a few months rehabbing his knee at the Boras Sports Training Institute in Southern California last fall, has also given Na a taste of what he can expect if he makes the United States his home.

"I love shopping!" said Na, joking that because of the size of his body (6-foot, 220 pounds) he can't find clothing in his size in South Korea. "I do a lot shopping in the United States. I love Abercrombie & Fitch and Lululemon. And baby back ribs are my favorite!"

And if one place made him feel like one day he could belong, it was visiting Dodger Stadium for the first time last September and watching Hyun-Jin Ryu pitch. Na was there when Ryu launched his first MLB home run off Antonio Senzatela of the Rockies before going on to record his 13th win of the season for the Dodgers. The previous year, Ryu became the first Korean-born pitcher to start a World Series game.

"When I entered Dodger Stadium, I felt a little nervous. Don't get me wrong, Korean baseball stadiums are really nice, but when you see Dodger Stadium ... that grass is sooooo green!" Na said. "It's so nice, the field conditions, the major league players, and seeing Ryu pitch. I had only watched major league players and major league stadiums on TV when I was playing in Korea, and it made me dream about playing in the major leagues next year. It was a really good experience."

Na added, "It's my dream to go to all 30 MLB baseball stadiums. I believe all 30 stadiums have their own charm. I would love to come to MLB because the world's best players are playing in the same league. And watching and playing against the best, I can improve myself as well. MLB and KBO can learn good things from each other. Baseball is one common language."