By Joseph Salvador Prescott isn’t expected to miss any offseason workouts. View the original article to see embedded media. Cowboys coach Mike McCarthy announced that quarterback Dak Prescott underwent successful surgery on his left shoulder at the beginning of the offseason on Tuesday. McCarthy, who is at the NFL combine, said he has “no concern” about Prescott’s availability for offseason workouts. McCarthy referred to it as a “cleanup surgery” and said Prescott is ”doing well,” according to Cowboy Maven. Prescott is coming off a season where he threw for 4,449 yards, 37 touchdowns and 10 in…