New York also announced that INF/OF Wily Mo Pena and INF Javier Valentin have been released.
Lopez, 26, posted a 19.29ERA in four relief outings with the San Diego Padres (2.1IP, 7H, 5R, 5ER, 3BB). He spent most of the season with Portland (AAA) of the Pacific Coast League where he had a 2.77ERA in 20 games with the Beavers. He struck out 23 batters and allowed just 27 hits in 31.0 innings of work (14R, 13ER, 13BB).
Pena hit .276 (40-145) with five home runs and 21RBI in 41 games with the Bisons.
Valentin, who had been on the disabled list since June 15 with a strained right shoulder, hit .260 (20-77) with three home runs and 10RBI in 23 games with the Herd.