The injury occurred while Blum was rounding first base after hitting a double during the Astros' split-squad game with the Indians.
"I jammed it in the bag," Blum said. "Making a turn at first base, I stuck it out. I hit the heel first and jammed it pretty good."
Blum will likely return to play on Wednesday night during a home game with the Braves.
In other injury news, Wandy Rodriguez continues to make progress after straining an oblique muscle during his outing against the Tigers on Friday. He threw only two pitches before exiting the game.
"Wandy won't miss more than a week, give or take another day on one side or the other," manager Cecil Cooper said.
Second baseman Kazuo Matsui was scheduled to fly on Sunday to Houston, where he will undergo a surgical procedure to repair an anal fissure that has hampered him for most of the spring. Matsui will rest for a week after the surgery but is expected to be ready for Opening Day.
If he is not ready, the Astros have options for second base. Blum and Mark Loretta are the front-runners to absorb playing time in the event Matsui needs to start the season on the disabled list.
"We've got depth," Cooper said. "That's why we signed Blum and Loretta, with the idea that they can play all over. It could be a platoon situation."
Jose Valverde (sore back) has not pitched since March 8, but he threw a bullpen session on Sunday and said that he felt fine. The closer hopes to pitch in a game in the early part of the week.
Also on the illness front, David Newhan returned to the team after missing a day with flu-like symptoms.
Alyson Footer is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.