Amari Cooper’s first return from an ankle injury lasted less than two full quarters.
Against the Chiefs in Week 14, the Raiders’ receiver was assigned to block on a play for running back DeAndre Washington, who was tackled into the back of his left leg. Cooper went down clutching at the ankle he originally injured in Week 12 against Denver, and has not played since.
Addressing reporters Friday for the first time since before the Broncos game, Cooper admitted to frustration with the injuries that have mostly kept him on the sideline for the past month.
“To be hurt and then to feel like you’re ready to play, to put in all that preparation and all that treatment and go out there and get hurt again - it can be tough a little bit mentally,” Cooper said. “But it’s football. You risk getting hurt every play out there.”
The Raiders hope Cooper’s second return is more lasting. Cooper was a limited participant in practice Friday, a day after head coach Jack Del Rio said the team hopes to have Cooper back Christmas Day against the Eagles on Monday Night Football.
Cooper said after practice the ankle “feels alright,” and that he’s “still working through it.”
Cooper had not missed a game in his NFL career before a Nov. 26 hit by Broncos safety Darian Stewart that left him with a concussion and ankle injury. He sat out the Raiders’ win over the Giants but was cleared to play in an important divisional game at Kansas City, with the Raiders and Chiefs tied for first place.
Asked Friday how he felt physically before that game, Cooper said: “I was healthy enough to play.” He was targeted on just one incomplete pass before aggravating his ankle and exiting with 6:39 left in the second quarter.
“It’s been kind of frustrating in that regard,” Cooper said. “Obviously you want to be out there and play. This is my job, you know what I’m saying? So, yeah.”
Cooper said he holds no ill will over the Nov. 26 hit by Stewart. Raiders head coach Jack Del Rio initially called the hit “vicious” before toning down his criticism the next day, saying it appeared Cooper had lowered his head before contact. Stewart was fined $24,309 by the NFL for the hit.
“I felt like it was a fair hit,” Cooper said. “I guess he got flagged on the play. I don’t know. Rules change.”
Injuries have only contributed to a difficult third year in the NFL for Cooper.
After becoming just the third receiver in NFL history with 70 or more catches and 1,000 or more yards in each of his first two seasons, Cooper has 42 catches for 499 yards and five touchdowns in 12 games this season. Nearly half his receiving total, though, came in one game - Week 7 against the Chiefs, when Cooper had 11 catches for 210 yards in a Raiders win.
It followed a four-game stretch in which Cooper had caught a total of nine passes for 51 yards. Cooper also dealt with a series of drops early in the season. Asked to assess Cooper’s season Friday, offensive coordinator Todd Downing likened it to that of the offense as a whole in being “a little inconsistent.”
“He’s certainly had his flash moments - the Kansas City game where he exploded for over 200 yards, and the first drive of the season against Tennessee he was making plays,” Downing said. “And there’s been some dips as well. But we’re all going to strive to be consistent as possible and continue to work to get better. So, a little bit of a work in progress I guess is how I would say it.”
Cooper’s effect on games isn’t always reflected in numbers. Quarterback Derek Carr said he has seen teams defending the Raiders differently in recent weeks with Cooper out.
“When people cover Coop, they bracket him, they try and match him, they try and in-and-out him, they try a whole bunch of different things,” Carr said. “When that doesn’t happen, the attention goes to (Michael) Crabtree, the attention goes to Jared (Cook), depending on the defensive personnel that they have. They’re able to roll coverages and make it hard for us.
“It’s one of those things that it’s next man up. That’s why sometimes if we’re not as efficient or things like that, we’re trying to do the same kinds of things and make plays, it just hasn’t worked out that way. One of those years where we haven’t been as efficient. It’s not an effort thing. It’s not guys not giving it their all and things like that, it’s just that we haven’t been effective.”
Cooper said his goal the final two weeks of the regular season is “to have two good games.”
“Hopefully he can get rolling,” Downing said. “I know he wants to finish the season strong, as we all do.”
Matt Kawahara is a San Francisco Chronicle staff writer. Email: mkawahara@sfchronicle.com. Twitter: @matthewkawahara