Matt Cassel, throwing a touchdown pass to Randy Moss this month, inspired college QB Mitch Mustain to choose USC for its style of play.

The Providence Journal / Glenn Osmundson

FOXBORO — Mitch Mustain is hoping lightning strikes twice.

Mustain, currently the backup quarterback at the University of Southern California, transferred to USC from Arkansas last year.

As he was considering a new landing spot, Mustain, of course, took a lot of things into consideration. According to the Los Angeles Times, one of the reasons he chose USC was Matt Cassel.

Cassel hadn’t started a game for the Trojans, but the program and the pro-style offense the team runs prepared him well enough for the NFL that the relative unknown heard his name called on NFL Draft weekend.

If Cassel was an inspiration to Mustain 21 months ago, imagine how Mustain feels now, inasmuch as the career backup has led the New England Patriots to a 6-4 record going into Sunday’s showdown with Miami.

“It’s nice to see a guy who’s gone in and put the work in and delivered when he finally got a break,” Mustain told the Times.

Told of Mustain’s comments yesterday during his weekly press conference, Cassel seemed pleased.

“I think for any backup anywhere, my story is one that gives inspiration and gives promise to some of those guys that are fighting for a position,” he said. “Just to continue to work hard, continue to put your best foot forward each and every day and quite possibly your dreams will come true.”

The problem for Cassel when he was drafted by New England was that he became the backup to a remarkably durable starter in Tom Brady. Cassel said there were times he doubted he’d ever get a chance to see anything but mop-up snaps.

“You think that. Every week in and week out, Tom would take a few shots here and there, but he would always get up and he is a very durable guy. You never know when your opportunity was going to come and you continue to press forward,” he said. “But there were times that I didn’t know whether or not I was ever going to get on the field, but I [kept] preparing myself like I was and thankfully for me I was able to get on the field and get an opportunity.”

Mustain, a redshirt sophomore, is looking up at the depth chart at Mark Sanchez, a junior.

Cassel played behind Heisman Trophy winners Carson Palmer and Matt Leinart at USC. Palmer was the established starter when Cassel joined the Trojans, but coach Pete Carroll has acknowledged that choosing Leinart over Cassel as the starter in 2004 was a very difficult decision.

Asked about being the backup to both players, Cassel politely pointed out that he wasn’t really supposed to be Leinart’s backup. In a bit of irony, the Bengals’ Palmer hasn’t played much this season because of an injury, and Leinart lost his starting job in Arizona to Kurt Warner.

“It is an interesting relationship. It’s more so that I was the understudy of Carson; when Matt came in it was more of a collaboration because I was the older guy and maybe knew more of the offense when he first got there,” Cassel said.

While Palmer and Leinart have been on the sidelines this season, Cassel has developed into a solid starting quarterback. Cassel says he talks to both, and now the three have the shared experience of being the top signal caller.

“Those guys have earned their way,” he said. “They were great college players and they are great professional players. I have a lot of respect for them. I’m just happy that I have an opportunity to play now and we are able to talk about those kinds of things.”

If Mustain and Sanchez both make it to the NFL, having five former Trojans from the last decade on professional rosters will be quite a feat for the school generally known as Running Back U.

smanza@projo.com