Bob Locker pitched for the Cubs during two different years - 1973 and 1975. !973 was a strong year for Locker. Probably his best in MLB. In 1973 he had 10 wins to go along with 18 saves and a2.54 ERA. Apparently when he was traded to the Cubs from the A's in 1973 for Bill North, he told the Cubs he would pitch one year in Chicago and then wanted to be traded back to the A's. The Cubs honored the request and sent him back to the A's for Horacio Pina in 1974. Unfortunately for the A's, Locker had to have surgery to remove bone chips and did not play in 1974. He was then traded back to the Cubs along with Darold Knowles and Manny Trillo for Billy Williams.
Locker was not able to repeat his strong play in 1975. In 22 games he won none and lost 1 with an ERA of 4.96. He was released by the Cubs in late June and never played in the majors again.