EARTH CITY, Mo. -- Long before defensive tackle Aaron Donald ever put pads on underneath his St. Louis Rams jersey, coach Jeff Fisher had high hopes for him.

Yes, the Rams drafted Donald with the No. 13 overall pick in May's draft, which would already indicate a certain amount of confidence in what he could accomplish. But many rookies don't come to the league with the level of expectation that Fisher and the Rams had for Donald when they selected him.

Even taking No. 2 overall pick Greg Robinson as an example, the Rams liked what he could do in the short term but were open about the fact that selecting Robinson was more of a long-term selection.

Aaron Donald (99) has lived up to the immense expectations the Rams placed on him, leading all rookies with seven sacks. Jeff Curry/USA TODAY Sports

That wasn't the case with Donald, and Fisher never made any bones about it. So when Fisher was asked Monday whether Donald has his vote for defensive rookie of the year, Fisher went beyond a simple yes.

“Yeah, I said that in the Spring when I saw him on the practice field," Fisher said. "I went on the record to say he has a chance to be Defensive Rookie of the Year. I haven’t changed since.”

The only thing that's changed since is that Donald has actually had a chance to live up to those expectations. And, to the surprise of nobody who watched him play in the spring and through training camp, Donald has more than lived up to the billing.

Donald had another sack Sunday against Washington, giving him one in each of the past four games and seven for the season. His seven sacks are the most among all rookies and is tied for fourth amongst NFL defensive tackles.

For what it's worth, Pro Football Focus' grading metric ranks Donald as the league's best at the position with a score of plus-30.6. PFF also has a statistic for what it calls "stops", which includes sacks and tackles for plays that are considered an offensive failure. Donald ranks second amongst defensive tackles with 30.

If those numbers aren't reliable enough, the Rams coaching staff also has Donald down for 21 quarterback hits and nine quarterback pressures.

Fisher has been around his share of talented young defensive linemen in his nearly two decades as a head coach but said he's yet to come across one like Donald.

“Well, not inside on the defensive line, no," Fisher said. "The way he’s playing is pretty impressive, week after week after week. That’s what we thought we would get out of him, and I think we’ve got more than we thought. He just loves to play, and he plays hard. He doesn’t draw attention to himself. He’s really smart and very talented physically. Those two traits result in the plays that he’s making.”

Whether Donald will be able to nudge his way into the conversation for Defensive Rookie of the Year remains to be seen. He didn't become a starter until Week 6, which limited his production a bit early in the season, and he doesn't play a glamorous position where he can rack up tackles like linebackers.

But if nothing else, we should have already learned that presuming Donald won't exceed our expectations is a fool's errand.