Ruiz had been sidelined with an oblique strain since April 11. Catcher Lou Marson was sent to Triple-A Lehigh Valley to make room for Ruiz, who was hitting .273 (3 for 11) before he got hurt.
While Ruiz returned, ace Cole Hamels could miss his next start at St. Louis on Tuesday. Hamels tested his injured left ankle in the bullpen. General manager Ruben Amaro Jr. said the results were encouraging, but indicated Hamels might be skipped when his turn in the rotation comes up.
Hamels, the World Series and NLCS MVP, has been plagued by injuries this season. His first start was pushed back because he had minor elbow problems in spring training. He left a start against Milwaukee on April 23 after getting hit in the shoulder by a line drive in the fourth inning. He left his next start when he hurt his ankle chasing a bunt in the fifth inning against Washington. Hamels is 0-2 with a 7.27 ERA in four starts.