Charles London was enjoying his job as an offensive assistant with the Tennessee Titans under former Penn State lineman Mike Munchak. He had received a couple of other offers after last season. When one of his old colleagues called him up this January, though, London couldn't turn him down.

Charles London, right, wears a lot of hats for Penn State.
"I knew from the day I met him I wanted to work for coach O'Brien again," he said.
The youngest member of Penn State's coaching staff has had a full plate in his first season in State College. London lost his top running back, Silas Redd, to transfer in August and had to deal with injuries to Bill Belton, Derek Day and Michael Zordich earlier in the season. As the team's recruiting coordinator, London also plays a key role in the team's future.
All of it, he said Thursday, has been made easier by his previous relationship with O'Brien, with whom he coached at Duke from 2005-06, when O'Brien was the offensive coordinator and quarterbacks coach under Ted Roof (now Penn State's defensive coordinator) and London was a grad assistant, then running backs coach.
"It does help me kind of knowing what to expect," London said. "I know what he's looking for, know what he expects of me. I'm starting to even get a feel for what he's thinking schematically."
O'Brien has also worked with offensive assistants Stan Hixon and Mac McWhorter at Georgia Tech and tight ends coach John Strollo was the offensive line coach at Duke from 2005-07. The familiarity has paid off this season, said London.
"There's a lot of synergy there in our offense, guys having a feel of each other," London said. "It really benefits us for game planning mode."
London said O'Brien helped mold his philosophies as a coach and that he also benefited from working under Munchak and from his three seasons as an offensive assistant for Chicago Bears head coach Lovie Smith. London's own style tends more toward that of Smith, who London never heard raise his voice, than that of the fiery O'Brien.
"I'm kind of a laid-back guy," he said. "If I was to go out and rant and rave, guys would see through that."
The Nittany Lions' current backfield has a lot of low-key personalities, and they've responded well to London.
"Everything he teaches he knows is going to help us down the road, whether it be here at the college level or the pro level," running back Zach Zwinak said. "He shows us everything we need to do, tries to improve our game."
London, who credited director of player personnel Bill Kavanaugh with helping keep Penn State's recruiting efforts organized, knows his best weapon in recruiting is the other nine men, including O'Brien, in the coaching offices.
"Each guy here on this staff is a veteran recruiter. Each has their own recruiting style," he said. "I let the guys run with that. … We spend 2-3 hours each night on recruiting after we watch practice."
London said Thursday that one day he hopes to be a head coach and that he likes the way O'Brien gained experience at a number of different positions and stops in his own career.
"I think anybody that's in this profession, you want to try to get to the top," he said. "I'd like to get where I could do different things and broaden my horizons, but right now I'm content coaching running backs."