Joey Votto is defending the decision to wait more than two weeks before getting an MRI that found torn cartilage in his left knee.

The Cincinnati Reds first baseman hurt the knee while sliding into a base on June 29, but didn't get an MRI because he didn't think the injury was serious. He kept playing and the knee improved, so he didn't feel a need for tests.

"I was improving, so I would say nobody's at fault here," the Toronto-born Votto said on Wednesday.

When the knee got worse over the weekend, he got an MRI that found the tear and led to surgery. He's expected to miss three to four weeks.

Votto started rehabilitation exercises on the knee at Great American Ball Park on Wednesday. He told reporters that he wouldn't have done anything differently in hindsight.

"I was feeling great," Votto said, standing on crutches in front of his locker. "Those four days off at the all-star game, then coming back, I was almost at 85 to 95 per cent [when] running. And then all of a sudden, it just started swelling up and it felt like I tweaked something."

'I was always taught to just stay out of the training room, play as much as you can. ... For better or worse, I think in the long run that's going to pay off for me and hopefully for the Reds.'— Reds' Joey Votto on delaying an MRI on his knee

The National League's 2010 MVP is known for his durability — he played in 161 games last season. He was batting .342 when he went on the 15-day disabled list, leading the National League in doubles, walks, on-base percentage and extra-base hits.

Votto said he felt something in the knee during a 3-2 win over the Cardinals on Saturday night, and it was sore a day later. He had a single and RBI double during a 4-2 win that completed a sweep of the Cardinals on Sunday, then told the team about the problem.

'Healed really quickly'

"I was always taught to just stay out of the training room, play as much as you can," Votto said. "If you can play, play. For better or worse, I think in the long run that's going to pay off for me and hopefully for the Reds. But I healed really quickly after the initial [injury]. We were really optimistic, hoping it was just something muscular.

"We're also trying to stay in first place and win the division. That's another reason I felt it was wise to wait it out and hopefully heal and help the team."

The NL Central leaders called up outfielder Xavier Paul from AAA Louisville before a game against Arizona, giving them a little help with the offence. Like Votto, Paul bats left-handed.

The outfielder went to spring training with Washington and started the season at AAA Syracuse. He was released by the Nationals on July 3 and signed a contract with the Reds last Thursday.

"I had an out with the Nationals, and I chose to take my chances with another club," Paul said. "The Nationals were great to me. They have a great bunch of guys, and they could win it. It's just that I needed a change. It worked out."

Paul gives the Reds a little more speed in the lineup as well, something they'll need while they try to get by without Votto.

"Right now, we've got to change our game a little bit because we don't have that power in the middle of the lineup with Joey out," manager Dusty Baker said.