Cardinals offensive lineman Earl Watford played nearly the entire second half at right guard against the Patriots.

The "Swiss Army knife" label given to Earl Watford by the Cardinals' coaching staff should be worn like a badge of honor.

The fourth-year pro worked at all five offensive line spots in training camp and the preseason, and D.J. Humphries shook his head as that registered in his mind.

"Kudos to Earl, man," Humphries said. "I know how hard it was just to switch from left tackle to right tackle. I couldn't imagine switching from left tackle to right tackle, and then going to guard, and then going to center. I don't think I could pull that off. I know every other team wishes they had somebody like that."

There's no question Watford holds value to Cardinals, but while Swiss Army knives are multi-functional, they are still a starter kit. The knife blade dulls quickly. The scissors won't cut much more than plastic. The screwdriver can't penetrate hard surfaces.

Watford could have a big task on Sunday if he must fill in for the injured Evan Mathis at right guard against the Buccaneers. If that's the case, he will aim to show he's as useful in reality as he is in theory.

"I'm trying to prove myself to my other teammates," Watford said. "They know I can do all these things, but when it counts, can they count on me?"

This is not new to Watford. He started the first two games of 2015 at right tackle in place of the suspended Bobby Massie, and filled in at left guard when Mike Iupati got hurt against the Seahawks.

Mathis injured his foot in the first half against New England, and after yo-yoing in and out of the lineup for a stretch, was done for the day early in the second half. Watford took over, but said the outing didn't go as well as hoped.

"I was prepared," Watford said. "I wasn't as technically sound as I wanted to be. I gave up some hits. That holding late in the game at a critical time (two plays before the go-ahead field goal attempt that missed) – I know better than that. I've got to be better than that. This week it will be on point."

Mathis practiced in a limited capacity on Thursday, so he may be back by Sunday. If it's Watford who gets the nod, he will be challenged immediately. The Buccaneers feature defensive tackle Gerald McCoy, a four-time Pro Bowler who can wreck games on the interior.

"(Watford's) got a big chore, especially if he's on McCoy," coach Bruce Arians said. "Just continue to play. He's been playing at a pretty good level, so just do your job."

Watford catches a break in that guard is his natural position. He also has time this week to mentally gear up for the possible start rather than heading into a game as a multi-positional backup.

"You can hone in on one thing technique-wise," Watford said. "Mentally, it's a little better, easier on your brain and on yourself. You don't have to stress over how many different people you've got to back up and your different responsibilities."

The Cardinals liked the idea of pairing the veteran Mathis with the inexperienced Humphries on the right side of the line this season. That's still the long-term plan, but if the Swiss Army knife has to be used, there's a comfort level.

Offensive coordinator Harold Goodwin said "I trust him if he goes into the game," and Humphries believes the chemistry is there with Watford.

"Whenever it's time for me to be called in, I've got to be prepared, got to be ready, regardless of where it is," Watford said.