Adrian Beltre collides with Jacoby Ellsbury (bottom) as both go for a foul ball. Ellsbury left the game with injured ribs, but X-rays were negative.
With an off-day scheduled for Tuesday, manager Terry Francona thought it possible for Ellsbury to be back in the lineup on Wednesday, with the left fielder replaced by Jeremy Hermida in Monday's inaugural game at the Twins' Target Field.
Ellsbury wasn't as sure about when he'll back, saying that he'll take it day-to-day.
He joked that if he was on the Patriots roster, "I'd be listed as questionable because they list everybody as questionable.
"And if this was football, where they only play once a week, I'd definitely be playing the next game,'' he said. "I'd have a week to recover.''
Ellsbury said it's still painful to take a deep breath and to lift up his left arm, but was relieved that nothing was fractured.
"I'm just grateful it wasn't worse,'' said Ellsbury, adding he watched a replay once because he wanted to see exactly what happened.
Ellsbury said that Beltre's knee didn't strike him flush in the ribs, and that if it had been lower more damage could have resulted.
Ellsbury and Beltre collided while in a pursuit of a foul fly by Kansas City's Mitch Maier down the left-field line. Ellsbury had gone into a slide to make the catch, while Beltre came sprinting down the line, unaware that Ellsbury was in his path.
"We did it textbook, infielder high, outfielder low,'' Ellsbury said. "Adrian said he just didn't expect me there. Two players going hard, don't know how it could have been avoided.''
Ellsbury hasn't ruled out playing Wednesday.
Gordon Edes covers the Red Sox for ESPNBoston.com. Follow him on Twitter.