As the raindrops started falling after a practice at Winter Park this week, Anthony Barr answered question after question about his return from a pair of knee injuries, the same kind of queries he has answered for the past 3½ weeks.

How does he feel? How frustrating has it been to sit out? When another reporter stuck his recorder into the scrum and asked for a third time how excited he was to finally play in a game, the skies opened up, Barr recited his answer once more, then jogged inside to escape it all.

"You want to play football," Barr said. "That's all I want to do is to play, be a part of a team and go out there and have fun. I love the game."

While some eye-rolling from the 23-year-old would be understandable considering the line of questioning has not varied much this summer, the scrutiny being placed on the promising outside linebacker throughout camp is also more than reasonable.

Barr emerged as one of the NFL's most exciting and productive rookie defenders last season and his 6-5, 255-pound frame paired with his athleticism can make him a unique weapon in coach Mike Zimmer's attacking scheme. But for that to happen, Barr has to be on the field, and he has been slowed by injuries in his career.

Barr was sidelined throughout the spring because of a right knee injury. After a week of training camp in Mankato, his surgically repaired left knee, the one that suffered a season-ending injury in November, swelled up, shutting him down again.

Two days after the team's first preseason game, Barr returned to practice. He suited up against the Tampa Bay Buccaneers last weekend and participated in pregame warmups, but did not play in that game. But Barr has been steadily building toward tonight's expected return to action against the Oakland Raiders at TCF Bank Stadium.

"He told [head athletic trainer Eric Sugarman] he feels the best he's felt in a long, long time, right now," Zimmer said Thursday. "He's having fun at practice, he's excited to get going and now we can start implementing him into things a lot more."

The Vikings used Gerald Hodges in Barr's spot in practices and preseason play while giving a few linebackers a chance to play in the nickel in his absence. But none of those players can replicate what Barr does, lining up as a defensive end on one play then running with a tight end in man coverage on the next.

Playing an every-down role before his left knee injury, Barr, the ninth overall pick in 2014, recorded 70 tackles and four sacks, knocked down three passes and forced a pair of fumbles, one of which he returned for a winning touchdown in overtime against the Buccaneers.

"You don't get a lot of guys like that, that are athletic and big and strong. He has all the tools you want," linebackers coach Adam Zimmer said early in camp. "Those are the ones you look back on later in your career and say, 'I'm glad I coached that guy.' "

For most of the spring and summer, though, the Zimmers had to coach him up in the film room. While his lack of on-field reps appears to be a concern when it comes to his development, Barr believes he actually benefited from having to spend more time watching.

"Mentally, if anything it made me better," he said. "Being able to watch film every day and watch practice every day, from that standpoint, I think that helped a lot."

From a physical standpoint, Barr said he feels like he is close to being 100 percent healthy. And Mike Zimmer said Barr's conditioning level, which was not where it needed to be at the start of camp in late July, is now satisfactory.

Barr, his knee issues hopefully behind him, said that just getting back on the field against the Raiders tonight would be considered a successful night for him. But Zimmer has made it clear he will hold Barr's performance to a higher standard.

"I just want Anthony to play like he's capable of playing. No different than anybody else," he said. "We've got a plan for him going into the game. We'll use him just like we would anybody else. Just because he dresses doesn't mean it's successful."

Still, considering the anxiety that surrounded Barr when his knee flared up in Mankato and that he hasn't played in nine months, simply returning Saturday will be a positive.

"I can't wait. It's going to be a great experience for me," he said. "It's going to be good to get back out there and just get my feet wet again. So I'm looking forward to it."