"He (Sachin) is fit for all the games," Singh told reporters here ahead of the team's clash against Rajasthan Royals at the Wankhede stadium here on May 20.
Asked about the injury, Singh said, "I really have no clue. I'm only focusing on IPL now. I really don't know what has happened."
Singh said the match against the Jaipur-based franchisee was crucial for Mumbai Indians, which has suffered two consecutive defeats.
"We didn't play well. We didn't bat well. We played way below our potential. We are quite aware of that. It's quite an important game for us and we need to win it," he said.
"Any loss will hurt. Especially a game that you expect to win comfortably. So we sat back, we just wanted to reflect on what went wrong and wanted to better that," he added.
The May 20 match will be last for leg-spin legend Shane Warne in the IPL and it will be last time that Warne and Tendulkar would be up against each other but Singh said they can't afford to get distracted by those things.
"We are focussed on what we want to do. It's important to play the way we want to. We know its Shane Warne's last game but it does not affect us," he added.
Asked whether the team was struggling to cope up with slow turners, he said it was a problem for everyone and not Mumbai in particular.
"It's a problem for everyone. Even in Chennai the wickets are very slow. No team has got a huge score unless the wicket has been very good. It's a question of adapting. Every team has to face that. The more you go into the tournament. The more you go into the season the wickets are going to get slower. We are preparing for that," he added.
Singh also denied that his team was bad-chasers.
"No we just batted badly. It was a easy score to get (against Deccan Chargers) but the batters didn't do the job. Overall we had a good game."