"I came to the ballpark not planning on starting him," manager Joe Girardi said. "He's not ready to go, and we'll continue to evaluate him every day, see what availability we have with him every day."
Kevin Russo started in Rodriguez's spot at third base against the Houston Astros, batting ninth.
A-Rod had an MRI on Friday that revealed tendinitis in his right hip flexor. The injury is a concern for the Yankees, but Rodriguez and the team sounded relieved that the groin tightness he's been feeling doesn't appear to be related to last year's hip surgery.
"I think anytime you get where you're looking in that region, you're going to start thinking about what happened the year before," Girardi said. "But being something completely different than the hip socket makes you feel a lot better."
Rodriguez left New York's 4-3 loss at Baltimore on Thursday night after one inning, hampered by tightness in his groin for the second time in a couple of days.
Girardi said Rodriguez "didn't really have a problem" until he played a 14-inning game on turf in Toronto last Saturday, which was a day game after a night game.
The three-time AL MVP is batting .290 with eight homers and 43 RBI.
"He felt better today," Girardi said after his team's 9-3 victory Saturday. "We'll put him in there when we feel he's ready."
In other news, Jorge Posada was cleared to catch Sunday. Posada has been limited to DH duties since coming off the disabled list June 2 after being sidelined with a broken right foot.
Posada was the designated hitter again Saturday. Before his third-inning grand slam, he was in a 4-for-34 slump since he was activated from the DL.
Speedy outfielder Brett Gardner took batting practice and said his sore left thumb felt good. Gardner, who sat out the previous two games, replaced Marcus Thames (strained right hamstring) in left field to start the fifth inning.
Thames went for an MRI, which was negative.
Second baseman Robinson Cano hobbled slowly down the line on a seventh-inning groundout after fouling a ball off his leg. He said he would be OK to play Sunday.