Deacon McGuire, 1908 44 years, 280 daysMcGuire's time with the Red Sox in 1908 was one pinch-hit appearance on (if my calculations are correct) August 24. He was released four days later and played one game with Cleveland, then returned two years later to play another game with Cleveland, and finish his career with one game with the 1912 Tigers (catching, at age 48).
Tim Wakefield, 2010 44 years, 46 days
Carl Yastrzemski, 1983 44 years, 41 days
Wakefield will have to play on or after May 10, 2011 to pass McGuire.