Practices squad receiver Kerry Taylor makes a grab Monday as teammates Larry Fitzgerald (11), Andre Roberts (12) and Early Doucet (85) look on. Sometimes, Taylor covers up his No. 18 for another number as he "plays" as a key opposing player.

Clay Matthews lined up on the outside of Nate Potter during Cardinals' practice a couple weeks ago and tried to beat the rookie left tackle to the quarterback.

Then Matthews tried it again, this time from another angle.

Except it wasn't really Clay Matthews. Matthews was actually in Green Bay preparing to do that exact same thing to Potter when the Cardinals played in Green Bay two Sundays ago.

Potter's foil instead was Tim Fugger.

Fugger, the rookie practice squad linebacker, traded in his red Cardinals' practice jersey for a black one with Matthews' number 52 on it. Depending on the week, a scout team player can be charged with simulating a top player from the Cards' upcoming opponent to help the Cardinals prepare.

That week it was Fugger. Leading up to the Minnesota game, second-year player Kerry Taylor played the role of the Vikings' Percy Harvin. Defensive back Greg McCoy donned the black jersey before Week 3 to imitate Philadelphia receiver DeSean Jackson.

Each player brought a realistic trait to the player they were simulating. Taylor is built similar to Harvin and he's fast. Fugger knows how to come off the edge. McCoy has Jackson-esque speed.

With Taylor, the Cardinals' received an added bonus. He spent last season with the Vikings as Harvin's understudy.

"It's cool," Taylor said. "You just try to give the defense the best look you can. Especially being in Minnesota last year, I knew what they were looking for so it was easy to do that."

Taylor studied Harvin during his time in Minnesota, and tried to pattern his game after the dangerous kick returner. That, coupled with his intimate knowledge of the Vikings' playbook, Taylor believed he was able to give the Cards' defense a "realistic" look of Harvin – sans the lightning-fast speed that only a select few in the NFL can match.

Despite the Cardinals losing both the Vikings' and Packers' games, the simulations appeared to work, according to the statistics. Harvin, who many are considering a strong MVP candidate this season, finished with just 10 yards rushing and 37 yards and a touchdown receiving.

"They took him out of what he likes to do best and made it hard for him," Taylor said. "So when I see that I feel like I did my job and gave the best that I could possibly give."

Matthews, who left the game in the third quarter with a hamstring injury, finished without neither a tackle nor a sack.

Fugger was given the honor of simulating Matthews, who was the NFC Defensive Rookie of the Year three years ago, because he was one of Vanderbilt's outside rushers last season and played outside linebacker in Indianapolis before signing with the Cardinals late last month.

While Taylor studied Harvin in person, Fuggar, who is an inch taller and five pounds lighter than Matthews and gives up about a foot of hair, didn't watch film of Matthews to nail down any tendencies or habits.

"If you ever watch Clay play, all he does is just go really fast and really hard," Fugger said. "So that's a little bit easier as far as fundamentally but you just have to have a motor."

McCoy, a rookie out of TCU, didn't study film of Jackson, either, per se. Instead, while in college, McCoy "studied" Jackson, as he did the league's top players, just by watching NFL games every Sunday.

"You've done a lot of studying on them already but just watching film with the rest of the guys and seeing some of the things they do, their habits and you try to bring it out here to the field and give the (defense) a better look," McCoy said.

McCoy was most intrigued with Jackson's speed and the Cardinals' speedster – McCoy ran a 4.4-second 40-yard dash at the NFL Combine in February – tried to replicate that speed. And it appeared to work. Jackson had three catches for 43 yards.

"I think we did pretty good," he said. "Did you see that game?

"We have a lot of fun imitating a lot guys that you've looked up to and guys that you've watched basically your whole college career. So you have a lot more fun than that because you're trying to be like somebody else at that time."

As much as Taylor, Fugger and McCoy tried to let loose and be someone else on the field for a week of practice, they injected their own respective personalities into their simulations.

But for a few days, anyway, Fugger, Taylor and McCoy can say they were Pro Bowlers.

"They work hard," coach Ken Whisenhunt said. "It's very hard to simulate other teams, players or schemes because you don't know exactly the timing of it or what they're trying to do. But our guys work hard. They do a nice job."