FOXBORO — When the Patriots’ rookies went through the annual pre-practice soaking the other day — courtesy of quarterback Tom Brady — not all the first-year players looked completely enthused about the situation.

Not linebacker Tyrone McKenzie. McKenzie has yet to play a game at the NFL level, but probably could have been excused from the exercise — after all, he missed all of 2009 with a knee injury, so he’s technically not a rookie.

But the South Florida product jumped it and took his soaking just like the rest of the new guys.

“I just wanted to take part in it,” the 24-year-old said with a grin when asked why he took the plunge. “I didn’t get a chance to do it [last year], and it looked like fun.”

McKenzie, who was selected in the third round of the 2009 draft, suffered a serious knee injury during rookie minicamp and was sidelined for the entire season. It was a trying time for the 6-foot-2, 243-pounder, who stuck around for most of the season last year, putting in time with the rest of the linebackers in the meeting room but never getting the payoff on the field.

“Last year, it was tough when you sit in the classroom all year and just learn and learn and learn but never put it into play,’’ McKenzie said. “It’s a whole different situation. You have to get in a classroom, learn it, and then put it out there on the field. [Organized team activities] were huge for me just to learn it and to go out there and put it on the field.”

McKenzie has been able to follow up a solid performance at the OTA’s with a very good first week of training camp. He provided what many believe to be the defensive highlight thus far — in a goal-line drill, he met running back Laurence Maroney in the hole, and delivered a crushing blow, knocking Maroney off his feet and drawing cheers from the rest of the defense.

These practices are invaluable for McKenzie, who is engaged in one of the best positional battles in camp. McKenzie, Gary Guyton and rookie Brandon Spikes are all vying for the inside linebacker spot opposite Jerod Mayo in New England’s 3-4 defense. Guyton went down with what’s being called a minor knee injury earlier in the week, which has allowed McKenzie and the rookie Spikes to get more reps at the position.

Overall, McKenzie has split his time between what appears to be the first and second defense. But when it comes to McKenzie’s development, the more reps, the better, no matter where he’s lining up.

“Tyrone is a smart kid — he really understands the defense. He’s good with the calls and the communication and adjustments and really understands what we’re doing,” said Patriots coach Bill Belichick. “He just needs the practice repetitions of actually doing it, taking on blockers, reading keys.”

“Linebacker is a position that’s so much dependent on a player’s instincts and his ability to figure out where the ball is going, and runs, and play-action passes, and making those kinds of decisions and quick recognition as soon as the play starts,” Belichick added. “There’s not a way you can prepare for that in the weight room or running laps around the track; you have to be out there with 21 other guys. These practices have been good for him, both in the spring here and in training camp.”

His injury aside, it’s been a long journey to the NFL for McKenzie, who played collegiately at three different schools (Michigan State, Iowa State and South Florida). After his mother was left unable to work by injuries suffered in an accident, he left school and was working from 11 p.m. to 7 a.m. at a Hampton Inn to support her and his three sisters.

After being taken 97th overall in 2009, he was praised by Belichick as being one of the most impressive draft picks he’s ever seen.

“Of all the players that I’ve talked to and we’ve interviewed this year and even through the years, Tyrone is one of the most impressive,” Belichick said shortly after New England drafted McKenzie. “Maturity, intelligence, what he’s done with the opportunities he’s had or that he’s had to overcome, how he’s dealt with them, how he’s made the most of them; it hasn’t been easy. Yet he continues to excel, jump over hurdles and overcome obstacles that I think would have derailed a lot of other people and/or football players.”

But on May 2, he tore his ACL in a drill at rookie minicamp. Sidelined for the entire year, he tried to make the experience work for him.

“Last year, it was a great chance for me to learn how to be a pro and me being around the guys and seeing how the season works,” he said. “I’m still learning as we speak.”

While the resilient McKenzie is clearly chomping at the bit for a chance to be known as more than just an inspirational story, he knows that there will be people out there who will draw hope from his journey, and he’s OK with that.

“I want to get my career started as a pro. I want to get out there and get after it,” he said. “But at the same time, if there are people out there who hear my story ... if there’s a kid growing up, coming out of a similar situation, if he hears my story, it might be able to help. I’ll never get over it — it’s part of my life, my past. But if my story can help benefit another kid, then that’s great.”