PITTSFORD, N.Y.—Buffalo quarterback EJ Manuel had what Bills coach Doug Marrone would only call “a procedure” on his left knee Sunday morning and will miss the rest of the preseason.

Marrone, who declined to characterize the medical attention the quarterback received as anything other than a “procedure,” says it was “very, very minor” and that Manuel has a good chance of returning before the start of the regular season.

Manuel was hurt in Buffalo’s preseason game against the Minnesota Vikings on Friday. He did not leave the game due to injury but had swelling in the knee Saturday morning. Marrone said that Manuel will miss the rest of the preseason and be evaluated daily after that.

The Bills chose Manuel out of Florida State with the 16th overall pick in the draft.