TAMPA, Fla. -- Andy Pettitte underwent treatment but did not play catch Sunday, one day after being scratched from a scheduled start due to back spasms.
"I was really feeling pretty good last night, and feeling good about it, what today was going to bring," Pettitte said. "Then I woke up this morning and it was kind of tight on me again. I've already lost two days. I don't want to set it back any. I'm just going to wait until tomorrow and hopefully it's a lot better and I can feel comfortable playing catch."
Pettitte is to make his first scheduled regular-season start, April 2 against Toronto.
"I'm definitely optimistic because I think it's going to clear up," Pettitte said.
Pettitte did admit his regular-season debut might be moved back a couple days.
"We've got options," Pettitte said. "It's just the first start of the season. I don't want to do that, but I want to make sure that I'm healthy and not go into the season with a bad back."
Pettitte's last spring-training start will likely be moved from Thursday to Friday.
"If I play catch tomorrow, I'm not going to throw a bullpen," Pettitte said. "I'm going to need to throw a good bullpen. So if I throw a good hard bullpen, I doubt I'll pitch on Thursday.
Yankees manager Joe Girardi said he was not overly concerned about Pettitte's injury.
"When a guy has tightness in his back, I don't worry about it as much as if it's in his elbow or shoulder," Girardi said. "Back spasms usually heal in three, four, five days."
Pettitte said he would need one more exhibition start to get his pitch count up. He threw 65 pitches on March 17.
In other news, Mike Mussina gave up one run and three hits in seven innings of a minor league game. he struck out four and walked one.
"It was OK," Mussina said. "It was worth doing. I was able to get something out of it, and be frustrated by what I couldn't do. I couldn't get the ball away as well as I would have liked."
Mussina has pitched in two straight minor league games. He is scheduled to make his final spring training start next weekend against the Florida Marlins.
"I'm evaluating execution," Mussina said. "I'm evaluating how it feels. Do I feel right? For the most part up to now I've been able to do just about everything I wanted to do."
Kei Igawa threw four hitless innings in the minor league game. He struck out eight and walked one.
Jose Molina, who caught Mussina, went 0-for-3 with a strikeout against Igawa.
Girardi said there are eight or nine candidates for three open bullpen spots.
Girardi said there are eight or nine candidates for the final three spots in the bullpen. ... Mussina threw 62 of 83 pitches for strikes. ... RHP Humberto Sanchez (elbow ligament replacement surgery) is scheduled for his first bullpen session on March 31. He could be ready for minor league games in May. ... RHP Andrew Brackman (elbow surgery) is throwing at 120 feet. The Yankees' first round pick in last year's amateur draft will not pitch this season.