Sources: UCLA's Jaylen Clark (Achilles) out for rest of season

UCLA forward Jaylen Clark is out for the season with an Achilles injury, sources confirmed to ESPN.

Clark suffered the injury in Saturday's regular-season men's basketball finale against Arizona, exiting the game with a leg injury and later returning to the bench with crutches and his right foot in a boot.

UCLA coach Mick Cronin said Tuesday that Clark had a lower leg injury and would miss this week's Pac-12 tournament. The school has yet to confirm Clark is out for the season.

Losing Clark would be a massive blow to UCLA's national championship hopes. He's the Bruins' best defender and one of the best defensive players in the country and has greatly improved his all-around game this season. He's averaging 13.0 points and 6.0 rebounds this season after putting up 6.7 points and 3.8 rebounds off the bench a year ago.

Clark was named Pac-12 Defensive Player of the Year on Tuesday, while also earning second-team all-conference honors.

Without Clark, expect UCLA to move senior David Singleton into the starting lineup. He started nine games earlier this season when Amari Bailey was out injured, and he played 31 minutes against Arizona after Clark's departure. Against the Wildcats, Singleton finished with 17 points and made five 3-pointers. He's shooting 43.4% from 3 this season.

UCLA, the regular-season Pac-12 champion, will play the winner of Wednesday's first-round game between Washington and Colorado in Thursday's Pac-12 tournament quarterfinal. The Bruins (27-4 overall, 18-2 in the Pac-12) are in the mix for a 1-seed in the NCAA tournament.

Stadium was first to report Clark would miss the remainder of the season.