Jaylen Brown recently returned to the starting lineup for the Boston Celtics after missing time with a knee ailment.

Despite Brown returning to the court, Danny Ainge revealed an alarming aspect of Brown's knee injury on the “Toucher and Rich” show:

Following Boston's loss to the Sacramento Kings on Feb. 3, it was discovered that Brown was experiencing some discomfort in his left knee. The former first-round pick would miss the next two games for the Celtics with what the team was calling knee soreness.

But with Brown returning to the floor, Ainge is saying that Brown is dealing with tendonitis in his left knee. While Ainge and the Celtics don't believe there will be long-term concerns with his knee moving forward, Boston is going to keep an eye on Brown's health. Of course, fans are not going to be happy to hear that Brown's knee injury could be something that could linger.

Brown didn't show any ill-effects from this knee issue when he did return to the court on Tuesday night in Utah. The Celtics star poured in 33 points on 12-of-20 shooting in 37 minutes. While his team lost, it certainly wasn't because of Brown.

In his first 21 games of the 2020-2021 season, Brown is having the best year of his five-year career in Boston. The California product is currently averaging a career-high 26.7 points per game on 52.2 percent shooting while also contributing 5.6 rebounds and 3.4 assists per game.

At 24 years old, Brown forms one of the best duos in the NBA with Jayson Tatum, making the Celtics a contender in the Eastern Conference. As Boston hopes to make a run to the NBA Finals, they hope that Brown's knee ailment doesn't become a glaring issue in the future.