Source: Washington Wizards' Davis Bertans (calf) out for rest of series against Philadelphia 76ers

Washington Wizards forward Davis Bertans has a Grade 2 calf strain and will be out four to six weeks, a source told ESPN's Adrian Wojnarowski.

An MRI done Tuesday revealed the extent of the injury, which Bertans suffered in the the Wizards' Game 4 victory over the Philadelphia 76ers.

He will be unavailable for the rest of the team's series against the Sixers, which the Wizards trail 3-1 heading into a must-win Game 5 in Philadelphia on Wednesday.

It's the second time this season Bertans has injured his right calf. He missed seven games from mid-March until early April with a calf strain.

Bertans left Monday's game in the second half after scoring a series-high 15 points while going 3-for-6 from 3-point range. For the series, he's averaging 9.3 points while shooting 35.1% from behind the arc, both down from his regular-season stats (11.5 PPG, 39.5% from distance).