Manager Joe Girardi said Monday that the plan was to have the right-hander throw about 55 pitches on Wednesday. Girardi said he wanted Chamberlain, whose brief major league career has been entirely as a relief pitcher, to get up to 75 pitches or more before starting a game.
But an injury to Ian Kennedy in Tuesday night's 10-9 loss to the Orioles in 11 innings might push Chamberlain into the starting rotation sooner than later.
"I think Joba loves to pitch, so I think if you told him he could pitch every day, he would," Girardi said. "He knows he is going to get a chance to compete."
Kennedy (0-3) left after three innings with a slightly strained muscle near his right rib cage. He gave up four runs, three earned, and two home runs. Kennedy was placed on the 15-day disabled list Wednesday.
"We DL'd him because we figured it would linger into a second start," Girardi said.
With Chamberlain unavailable Tuesday night, closer Mariano Rivera pitched the ninth and 10th innings and held the Orioles scoreless. But in the bottom of the 11th, with New York ahead 9-8, right-hander LaTroy Hawkins [25 hits allowed in 24 innings, 6.75 ERA] entered and allowed the winning runs on three hits and two walks.
Chamberlain threw a career-high 40 pitches in long relief stint on Saturday.
"We could move Andy [Pettitte] up to that date if we wanted to," Girardi said. "[Chamberlain] is a possibility that he can throw sometime after this and give us a start. We'll take it step by step."
Girardi said in order for Chamberlain to be considered for a start, he would have to be used for an extended outing and then see how he felt afterward. Chamberlain was expected to pitch Wednesday night against the Orioles.
"Somehow we have to get 50-55 pitches in him in order to increase [his endurance] and strengthen him. But you have to see how he comes out of it physically and how he feels two days afterward," Girardi said. "I can't tell you 100 percent that he is going to take that spot. I have to see what happens tonight first."
The Associated Press contributed to this report.