CHICAGO -- Players who collide with burly Brewers first baseman Prince Fielder usually are worse for the wear. Johnny Estrada got lucky.

Estrada, Milwaukee's catcher, suffered a bruised left knee after a seventh-inning collision with Fielder and had to leave Monday's game against the Cubs. He was held out of the lineup Tuesday, but acknowledged that it could have been much worse.

"I was scared," said Estrada, who lay on his back for a few moments before walking off the field. "I've never had a knee injury before. When he ran into me, my knee was straight, so I felt the pressure and went to the ground and stayed on the ground. I wasn't in any pain, but they made the decision to pull me out to be on the safe side."

The 6-foot-0, 262-pound (according to the team's media guide) Fielder has done some damage in the past. The most dramatic incident was last May 4, when Fielder bowled over Giants catcher Todd Greene at home plate in a Brewers win, knocking the baseball loose and knocking Greene out of the game. Teammate Geoff Jenkins suffered a concussion on June 4, when he and Fielder collided while chasing a foul pop down the right-field line. And in mid-July, Diamondbacks first baseman Conor Jackson missed two games with a strained shoulder after applying a swipe tag to Fielder, who was barreling down the line.

On Monday, Estrada and Fielder both converged on Felix Pie's bunt. The ball fell safely to the grass along the first-base line, and Fielder's momentum carried him into Estrada's leg, hyperextending Estrada's left knee.

"I think I could have caught it, but I heard him say, 'I got it! I got it!' at the last second, so I pulled up," Estrada said. "It was a freak play."

Said Brewers manager Ned Yost: "I was a little nervous that we wouldn't have Johnny for a while. We got lucky."

Estrada said he was available for pinch-hitting duties.