Karl-Anthony Towns has suffered a left meniscus injury, and doctors are evaluating whether that will require the Minnesota Timberwolves All-Star to miss a significant period of time, sources told ESPN on Thursday morning.

Towns is undergoing further evaluation to determine whether an immediate procedure is required, or whether there are rehab options that could return him to Minnesota’s lineup in the more immediate future, sources said.

A decision is expected soon, sources said.

The timing is terrible for Towns and the Timberwolves (43-19), who are tied for the No. 1 spot in the Western Conference standings with the Oklahoma City Thunder.

Towns has averaged 22.1 points and 8.4 rebounds while shooting 42% from 3-point range in 60 games this season. The Timberwolves have a deep and talented front line that includes Rudy Gobert and Naz Reid.