Though all four players have been mentioned in published reports as being residents of an on-campus apartment where police found a small amount of marijuana in a search Tuesday night, none had been charged with any crime at the time of this writing.
The same sources said each player's equipment remained in his locker in the Lasch Football Building as of Wednesday night.
One source said head coach Joe Paterno was taking a wait-and-see approach on the apartment search matter but would not elaborate further.
Penn State's primary football spokesmen could not be reached for comment.
Evans and Koroma are both starters on Penn State's defensive line, the former an All-America candidate at end and the latter a key figure at the depleted tackle positions.
Wallace is a cornerback who was slowed in the preseason by a pulled hamstring. He saw limited action in the season-opening win over Coastal Carolina last weekend but is expected to be a starter when completely healthy.
Quarless has had several brushes with the law during his time at Penn State and was suspended from the program for the spring semester. He is listed as the team's second-string tight end.
The Nittany Lions face Oregon State at Beaver Stadium Saturday.