The quad ailment is completely unrelated to the knee injury McDavid suffered at the end of last season, Holland added, according to Sportsnet's Chris Johnston.
However, the forward's absence is a devastating blow to Edmonton's postseason chances. The Oilers sit second in the Pacific Division with 64 points, but they're in danger of falling out of the crowded Western Conference playoff picture.
If McDavid is out exactly two weeks, he'll miss seven games. If he misses exactly three weeks, Edmonton will be without its captain for 11 of its final 27 contests.
McDavid's recorded 81 points this season, the second-highest mark in the league behind teammate Leon Draisaitl's 85.