De'Von Achane has been one of the NFL's best stories this season. The Miami Dolphins rookie running back has seven touchdowns the past three games and a 12.1-yard average per rushing attempt, which should not be possible in the NFL.

But now he's dealing with a knee injury.

Dolphins coach Mike McDaniel said he didn't know how Achane was injured in Sunday's game and apparently tried to play through it, and the team evaluated him Monday, according to Adam Beasley of Pro Football Network. McDaniel wouldn't speculate on whether Achane could miss some time, though ESPN's Adam Schefter reported Tuesday that Achane is looking at a possible multi-week absence.

One reason the speedy Achane fell to the third round of the draft was his size. He was just 5-foot-8 and 188 pounds at the NFL scouting combine, and backs of his size rarely can handle a big workload as an NFL running back. Achane dealt with injuries in the preseason and now has a knee injury after three games in which he split time with Raheem Mostert.

Achane has added an exciting element to an already fast Dolphins offense. He has 460 rushing yards on just 38 carries, which is unheard of. He also has 67 receiving yards, including a couple of touchdowns catching the ball.

The Dolphins will hope Achane can recover quicker than expected. Considering how quickly Achane has helped boost the Dolphins offense to historic levels, Miami will sorely miss his production while he's out.