Lee was out of the starting lineup for the opening game of a series against the Cincinnati Reds. He said there's no telling when he'll be able to play.
"It's still pretty sore," he said. "I guess I just get treatment and see how it goes."
Lee got hurt when Sanchez slid knee-first into his ribs while they were chasing Mark Kotsay's shallow fly ball during a 5-0 win over Milwaukee on Sunday. He was taken off the field on a cart.
"There was some sharp pain that was way up there on the scale," said Lee, who hadn't talked to reporters about the injury until Tuesday. "It felt like somebody was pushing everything from the inside out, and there was pretty sharp pain."
Tests at a hospital found no fracture. Lee flew to Cincinnati on Monday evening, after the opening game of the series was postponed because of rain.
Lee said nobody was to blame for the collision.
"That's a ball that you're in the middle of nowhere and we both felt we had a chance to catch it," he said. "If I just keep going straight in, you're probably talking to Sanchez [about an injury] instead of me. Basically, I saw his shadow coming and I kind of slid away from him."
Lee said the ribs bothered him more when he simulated a throwing motion than when he acted as though he was swinging a bat.
"We're going to wait and see how he is after treatments," manager Brad Mills said. "We're going to make sure he's able to do everything before we really look at him to go back in the lineup."