Devlin, however, has left the team. And the Lions are without a tested substitute should a vicious Trojans defense drive Clark to the sidelines.
It is no secret that when Penn State meets the Trojans on Thursday in the Rose Bowl, Clark will be under siege.
"They're very aggressive, and they're going to find out how tough a quarterback is," Penn State quarterbacks coach Jay Paterno said. "I don't think there's intent. But football is a physical game."
Fifth-year senior Paul Cianciolo is the backup. Some, including USC coaches and players, said the Lions would likely move wide receiver Derrick Williams under center rather than toss a green Cianciolo to the wolves.
"We heard about [Devlin's] quitting," Southern Cal linebacker Brian Cushing said. "Their backup, I think, is Derrick Williams. Knowing that, you never know what we're going to do."
The Trojans' defense is tops in the country in fewest points and yards allowed per game, with 7.8 and 210.6, respectively. Some consider it one of the best ever. The unit is led by two consensus all-Americans - linebacker Rey Maualuga and safety Taylor Mays - and three seniors who will play in the Senior Bowl next month.
"They have exceptional talent, exceptional speed," Penn State offensive coordinator Galen Hall said. "You look at their defense and it doesn't have a glaring weakness."
While he expects to be under duress, Clark doesn't imagine that USC would increase its pressure for the sole purpose of thumping him out of his shoes.
"Even if we still had more quarterbacks, I think they would pin their ears back and blitz," Clark said "That's part of their game."
However, he added: "But they're real intense. Sometimes they hit late and let you know that they're there."
Said Jay Paterno: "Everybody knows the most important position on the field is quarterback. You knock the guy out of the game - I'm not saying that's what they're trying to do - but they're going to try and make you sore."