Before beginning his workouts, Ruiz was optimistic.
"I feel great," said Ruiz, who was 1 for 5 in his two games over the weekend. "I have been moving good and I am not afraid to go hard."
With Erik Kratz out with a left knee injury, the Phillies have been depleted at catcher, going with Humberto Quintero and Steven Lerud.
Utley was placed on the disabled list May 23 with a strained right oblique muscle in his midsection.
"Chase is probably going to go out on a rehab here pretty soon, within the next 24 to 48 hours, we think," Amaro said.
The Phillies said they would know more after the pregame workouts.
Utley says he isn't sure how long he will need for a rehab stint.
"Obviously, I want to get back, but I also want to make sure I don't reinjure it," said Utley, who is hitting .272 with seven home runs, 25 RBIs, and an .814 on-base-plus-slugging percentage. "So I have to play it smart."
Utley says he has made obvious progress in the batting cage.
"I feel more comfortable doing it," he said. "When I first started swinging, I was obviously a little apprehensive, but it's going well."
Horst on DL
John Lannan was activated off the disabled list to pitch on Monday and the Phillies placed Jeremy Horst on the 15-day disabled list with a left elbow strain, retroactive to June 16. Horst strained his flexor-pronator muscle, Amaro said.
"It was kind of tight and rather than try to push him, it was probably important for us to shut him down and make sure it is not serious," Amaro said.
Amaro said that Horst probably would have an MRI exam on Tuesday.
Horst is 0-2 with a 6.38 ERA. He last pitched Saturday in Colorado, allowing three earned runs in one inning.
Push for .500 - again
Phillies manager Charlie Manuel was asked before the game where the Phillies needed to be positioned when Ruiz and Utley come back from injuries.
"I think if you're around .500 at the all-star break, or two or three games [above] . . . I think that will determine how much we have to push the second half of the season," he said.
The Phillies were four games under .500 entering Monday's game and had 26 games left until the all-star break.
Inquirer staff writer Bob Brookover contributed to this article.