LOS ANGELES -- Los Angeles Chargers quarterback Justin Herbert, who has been nursing a high right ankle sprain and is questionable for Sunday's game against the Kansas City Chiefs, is preparing to play, sources told ESPN's Adam Schefter.

Herbert successfully finished the work week without any setbacks and feels better this weekend than last, helping his chances to play Sunday, sources told ESPN's Jeremy Fowler.

Herbert sprained his right ankle in the Chargers Week 2 win over the Carolina Panthers. Ahead of the team's Week 3 game against the Steelers, Herbert hobbled and missed two days of practice but ultimately started against the Steelers. However, Herbert aggravated the sprain in the third quarter of that game and didn't finish.

Herbert left Pittsburgh in a walking boot after the 20-10 loss but said Wednesday that the aggravation hadn't set him back.

"I feel better than I did last Wednesday," Herbert said. "And so as long as we keep moving forward and we keep getting better, we're not taking those setbacks. I think we're moving in the right direction."

Unlike the week leading up to the game against the Steelers, Herbert practiced every day this week, the team listing him as a limited participant in the daily injury report.

Herbert said he competed in 7-on-7 drills and was doing everything he could to be out there.

The Chargers have a Week 5 bye, and the team had conversations about Herbert sitting out this week to rest and recover, but Herbert said Wednesday he "didn't think that's the way we're heading."

Herbert will go into a less-than-ideal situation Sunday with left tackle Rashawn Slater (pectoral) out and right tackle Joe Alt (MCL sprain) doubtful. Alt hasn't practiced all week but worked off to the side with a trainer during practice.

Still, Herbert said he has faith in the team's backups and isn't concerned about aggravating the injury Sunday.

"I don't think worrying does too much. It doesn't help too much," he said. "Take it day by day to see how it feels, and if it is an issue, then it's not safe to go out there and not smart to go play, but it has gotten better."