The Memphis Grizzlies have been rocked again by injuries on the eve of the playoffs.

Defensive specialist Tony Allen is out indefinitely after being diagnosed with a strained calf in his right leg, the team announced Thursday.

Adrian Wojanrowski of The Vertical reports that Allen would require a month to recover from his injury, thus knocking him out of the Grizzlies' first-round series with the San Antonio Spurs.

Allen would have likely drawn the unenviable defensive assignment of checking Kawhi Leonard, not only because Allen is a perennial All-Defensive Team staple, but because the Grizzlies have no one else who is capable.

One of Vince Carter, James Ennis, or Andrew Harrison will need to step up in Allen's absence. None of the three is nearly up to the task of keeping an MVP candidate in check.

The 35-year-old Allen averaged 9.1 points, 5.5 rebounds, and 1.6 steals per game this season.