The reigning NL MVP is expected to miss eight-to-ten weeks - instead of the reported six-week timeline - although the team will get a second opinion. While the injury isn't expected to impact Yelich long term or require surgery, the timeline rules him out for the remainder of the regular season.
Earlier Thursday, Stearns told WTMJ that it's very unlikely Yelich would be able to play in a potential World Series.
"At this point, what we're assuming and playing for is that Christian is not going to play again this season in any capacity," Stearns said.
Yelich sustained the injury after fouling a ball off his knee in the first inning of Tuesday's game against the Miami Marlins.
He's a top contender for the National League MVP Award after batting .329 with an MLB-leading 1.100 OPS and a career-high 44 home runs in 130 games this season.
The Brewers are riding high despite Yelich's injury, having won six straight games to move into a tie with the Chicago Cubs for the second NL wild-card spot.