Justin Washington has a lot to prove, and he knows it.

Last year, Washington was suspended for the first five games of the season by head coach Rich Rodriguez due to an “unspecified violation of team rules.”

“It was tough to sit and watch the team play,” said Washington, a defensive lineman. “But I knew I had to do my consequences for what I had done.”

Arizona needed all the healthy bodies it could get on an injury-riddled defensive line, so with his suspension, Washington earned himself a spot firmly in Rodriguez’s doghouse, and he had some work to do if he wanted to get out of it.

“Justin, frankly, wasn’t ready to play football to our standards in the first half of the year,” Rodriguez said.

Washington and Rodriguez wouldn’t disclose what Washington did to warrant the suspension, but regardless, he eventually worked his way back onto the team and into its defensive line rotation.

He was back by Arizona’s sixth game against Stanford and recorded one tackle in limited action.

“I think it was a little shaky in the beginning because I was out for a while,” Washington said, “but the team got around me and accepted me back in and I caught on from there, just fit in with the team and caught on their lead and eventually caught up.”

Added linebacker Jake Fischer: “He just needed a little bit of time to himself last year. He was going through some things, but he’s got it all squared away now and he’s committed to the football team.”

Still, his stance with Arizona entering his senior season is noticeably different from when he was entering his sophomore one.

In short, things haven’t exactly gone according to plan in Washington’s collegiate career.

He had a stellar freshman year in 2010 and received first-team Freshman All-America honors from Sporting News.

But the next year he suffered a knee injury in week six, had a severe allergic reaction to a pregame meal at the Alamo Bowl, had shoulder surgery a month later to repair a torn labrum in his right shoulder, missed all of spring ball and during the summer suffered from severe weight loss.

And then last spring, Rodriguez’s first at the Arizona, Washington was charged with criminal trespassing for his alleged role in a campus-area brawl. The charges against Washington, and four other UA players, were dropped in May.

His performance suffered on the field too. A few weeks into his sophomore year, before he injured his knee, he already lost his starting job to a freshman (Saniella Fuimaono, no longer at the UA). And since getting six sacks and 11.5 tackles for loss in 12 games as a freshman, Washington has one sack and two tackles for loss in 17 games as a sophomore and junior.

“I know I messed up a lot in the past and everything,” Washington said, “so I’m just working on the future and just trying to be consistent, be more positive and just try to be here for my team all the time, not just some of the time with injuries. I’m trying to be here all the time.”

There’s no one to blame for Washington’s recent struggles but himself, says offensive line coach Bill Kirelawich.

Washington — who is 6-foot-2 — ended last season listed at 268 pounds, which is about the average weight for a collegiate defensive lineman. As of Wednesday, though, he was at 250 pounds.

“Right now, for me, he’s underweight,” Kirelawich said. “I’d like to see him gain some more weight. I think he’s a terrific natural football player, but the way he plays, he needs to be bigger. For this season coming up he needs to be about 20 pounds heavier.

“If he has any illusions of playing in the NFL, he better gain some weight.”

Washington’s goal is to get into the 265-275 pound range, which he said “is not easy.” But it wasn’t easy to get six sacks as a freshman, and it certainly wasn’t easy working his way back onto the roster last year. Now, if he wants to contribute, Kirelawich and Rodriguez said he’ll have to prove himself all over again.

“I felt like I let the team down when I got suspended,” Washington said. “So my whole mindset was just working hard to get back with the team and prove to them I should be a Wildcat, be a part of this team and be on the same field as them.”