PHILADELPHIA -- Right until the end, Carlos Ruiz hoped he could play through the plantar fasciitis in his left foot. But after an MRI revealed a partial tear, he had no choice.

Ruiz was placed on the 15-day disabled list Saturday, although he's expected to miss four to six weeks. He'll be re-evaluated in two weeks. Infielder Hector Luna was recalled from Triple-A Lehigh Valley to take his spot on the roster.

"I feel real sad, because I was thinking it would maybe be day by day, you know? But there's nothing I can do except rest and then make sure when I come back I'm ready to help the team," said the All-Star catcher, who arrived in the clubhouse wearing a walking boot.

Ruiz first began to experience discomfort when the Phillies were in Los Angeles 2 1/2 weeks ago.

"It was real mild when it started," he said. "And I wanted to stay in the lineup, because that's what you do. But it was getting worse every day. I had good days, like that last day in Atlanta [on July 29]. I was feeling great, less pain than before. But then it got me real good and I felt that it had to be something, because there's no way that I'm going to feel OK one day and then feel real bad the next day."

Noted manager Charlie Manuel: "Chooch is a big part of our lineup. It's just goes to show how you can improve, what hard work will do for you. He went from being an eight-hole hitter to our cleanup hitter. He's having a tremendous year, not only with a bat but calling a game."

Ruiz is batting .335 and had already reached career highs in home runs (14) and RBIs (58).

"I'm having my best season, but that's life. That's baseball. I was real sad when I called my family, because I never expected to be out this long. But it happened, so I'll have to keep working," he said. "I don't know how long it's going to be. I hope less than a month."