MESA, Ariz. -- The Cubs' pitching rotation is set, but they may need to find room for lefty Ted Lilly as early as the third week in April.

Carlos Zambrano will start Opening Day on April 5 in Atlanta, and be followed by Ryan Dempster and Randy Wells. On Monday, Cubs manager Lou Piniella said Carlos Silva will follow Wells and Tom Gorzelanny will be fifth. The Cubs need five starters in the first month, and will not skip anyone, barring any changes because of the weather.

Lilly, who is rehabbing from arthroscopic surgery on his left shoulder, has four more Minor League starts to make before he's ready. He will start Tuesday at Fitch Park in the Cubs' Minor League camp and throw 45 pitches. Lilly then will go every fifth day and increase his pitch count each outing so he throws 60, 75 and 90 pitches, respectively.

"Once we get to that point, he's ready to join our staff," Piniella said. "If this thing stays accurate, it's 20-some days from now."

Which means Lilly's first start could be April 21 against the New York Mets.

The Cubs have yet to determine where Lilly will pitch those tuneup games but do want him to go where he won't have to worry about cold weather.

Gorzelanny will start Tuesday and Zambrano on Wednesday in the Cubs' split-squad game against the Angels in Mesa. The team will send Minor League pitchers to Milwaukee to face the Brewers in the other split-squad game. Silva will make his final tuneup on Thursday.

Wells started Monday and also will pitch Saturday in the Cactus League finale against the D-backs at Chase Field. Expect to see all the relievers in the two final games as well, including lefty James Russell, who has yet to give up a run in 11 innings over nine games this spring.

Monday was Wells' longest outing of the spring, and he gave up one run on seven hits over 5 2/3 innings against the Reds.

"The sinker is almost there, the changeup is coming around real good, the slider is getting better," Wells said. "Hopefully, in the side session and next start, I'll get it where it needs to be."

It's quite a different spring for the right-hander. Last year, he was being considered for one of the final spots in the bullpen but was eventually assigned to Triple-A Iowa.

"I feel like I've barely pitched this spring," Wells said. "It's weird -- I'm not sitting in the bullpen every day. I'm just itching to go and itching to be better than last year.

"It'll be kind of weird getting on a charter jet rather than the commercial ones to Albuerquerque [for a Minor League game]."

This will be Wells' sophomore season in the big leagues and he said not to expect anything different from last year.

"It's just, 'Do your thing and hope for the best,'" he said. "Chuck and duck, so to speak. I don't trick anybody. I sink the ball and change speeds."

It is a different feel for the team from a year ago.

"This is a better ballclub than last year, there's no doubt about it," Wells said. "Our versatility, camaraderie, call it whatever you want -- everybody likes each other, everybody's having fun. Guys like Kevin Millar and Marlon Byrd make all the difference in the world in the clubhouse. When you come in having fun, it's a lot easier to go out and have fun on the field."

Byrd is very talkative.

"He's awesome," Wells said of the outfielder, one of the few new additions to the team. "He doesn't shut up. He's always positive. I don't think I've heard a negative comment come out of his mouth in Spring Training.

"I don't think there's a guy in this clubhouse who thinks they're better than anybody or higher than anybody," Wells said. "It was the same feeling with the '08 team. You see guys like Mark DeRosa and Ryan Dempster and Ted Lilly, and you think, 'Oh my God,' and then they're ripping on you like you've known them for 20 years. It's the same feeling this year, and it's fun to be here."