Ruf said he had been feeling some tightness in his oblique for about a week, but he did not consider it anything serious, so he made no mention to the athletic training staff. He felt he would be fine if he simply took more time to warm up and stretch before workouts and games.
"It was one swing [Thursday during batting practice] that kind of took it to another level," Ruf said.
Ruf could not help but think about the Opening Day roster implications after it happened. He had a good chance to make the team as a reserve outfielder/first baseman.
"Just when I was experiencing tightness, that kind of crossed my mind," Ruf said. "When that swing happened, it was very disappointing."
Freddy Galvis also has been hospitalized with a MRSA infection. Galvis and Ruf will join left-hander Cole Hamels and right-handers Mike Adams, Jonathan Pettibone, Ethan Martin and Miguel Alfredo Gonzalez on a crowded disabled list with Opening Day just 10 days away.
The loss of Galvis and Ruf has considerable implications for the Phillies' bench. The Phillies have considered carrying a six-player bench the first couple weeks of the season, as they only need four starting pitchers until April 14. If the Phillies still plan to carry six bench players they could carry outfielders Tony Gwynn Jr., Bobby Abreu and John Mayberry Jr.; infielder Kevin Frandsen; and catcher Wil Nieves. Infielders Ronny Cedeno or Reid Brignac could take the sixth spot.
"We have eight days to look at everybody and it creates an opportunity," Phillies manager Ryne Sandberg said. "Not to make any decisions right now, but I'm going to look at everybody. We have eight games."
Chase Utley spent nearly a month on the disabled list last season with a strained oblique, and Carlos Ruiz spent three weeks on the DL in 2009 with the same injury.
Todd Zolecki is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.