(CBS) Cubs catcher Willson Contreras is projected to miss four to six weeks after an MRI on Thursday revealed he has a moderate right hamstring strain.

The worst-case scenario of a severe hamstring tear has been avoided, and Contreras will need rest and rehab to address the injury. He will be re-evaluated in two weeks, and a four to six weeks is the typical recovery timeline.

Contreras was hurt when he was running out a groundball in the eighth inning of a loss at San Francisco on Wednesday.

The 25-year-old Contreras is hitting .274 with 21 homers, 70 RBIs and an .861 OPS. He leads all catchers in the game in homers and RBIs. Contreras has been particularly hot of late, hitting .324 with five homers and 13 RBIs in his past nine games.

“He’s a key guy for us, carrying us offensively,” Cubs president of baseball operations Theo Epstein said on 670 The Score on Thursday. “Energy every single day, one of our best players.”

Recently acquired Alex Avila will be Chicago’s primary catcher with Contreras out, while Victor Caratini is being recalled from Triple-A Iowa to serve as the backup.

Entering play Friday, the Cubs led a tight four-horse race in the NL Central by a game over the Cardinals, with the Brewers two games back and the Pirates three games back. On the early side of the timeline, if Contreras returned exactly at the four-week mark from the day of his injury — Sept. 6 — he’d miss 25 games.

On Thursday, Contreras thanked everyone for their support on his way to get the MRI.

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