The Cubs rotation will be Ryan Dempster, Matt Garza, Jeff Samardzija, Chris Volstad and Paul Maholm. Wells, 29, did not get a spot even though he did not give up a run in 7 1/3 innings over three Cactus League appearances.
"Randy had a real good spring and we made that clear to him," Cubs general manager Jed Hoyer said. "It wasn't for his lack of effort.
"We came in here with seven starters competing for five jobs. Travis [Wood] has a really bright future with us but he struggled a little bit this spring and needs to go to Triple-A and regain what he had in 2010. Randy pitched real well and I thought he put his best foot forward. Jeff and Chris pitched a little better."
The Cubs did consider using Wells in long relief but instead consider him the sixth starter.
"We're not going to play with five starters all year," Hoyer said. "We need him stretched out in Triple-A. That was the message -- yes, you're not in the rotation to start the season but that means very little in a six-month marathon. I'm sure he'll make a lot of starts for the Cubs this year."
There are plenty of teams looking for starting pitching but Hoyer said the goal this year was to make sure they were protected.
"The minute you think you have depth, you don't have depth," Hoyer said.
Wells won a spot in the rotation last year and after coming back from his forearm injury finished 7-6 with a 4.99 ERA in 23 starts. He had been pushed back in the Cubs' spring rotation, so he should have gotten a little heads up.
"Usually when this happens, you've had a rough spring or haven't been pitching well," Wells said. "I feel I've thrown the ball well in a variety of different roles.
"I'm not going to sit here and lie and be the guy who says I'm not disappointed because I am," he said. "It is what it is. It's a point in your career where you have to buckle down and you know what you have to do. It's a wake-up call to see it's not that easy to stay here. Hopefully next time I get called up, it's the last time I have to deal with this."
Samardzija could definitely relate. He's been called into the manager's office before and told he was headed to the Minors.
"It's not fun, man," Samardzija said. "You've got a lot of people supporting you and a lot of people pulling for you to get to where you want to go. It's hard to get past the feeling that you let them down. The truth is there are a couple things you have to work on. For me, personally, I had to work on a lot of things.
"To get sent down is tough ... but a lot of times it'll show you who you are, whether you bounce back, keep fighting or pack it in," Samardzija said. "It's a crossroads. Randy will be fine. He throws a lot of strikes, keeps the ball down in the zone. He'll be a big part of the team this year eventually."
Cubs manager Dale Sveum said Wells did well but Samardzija and Volstad "threw the heck out of the ball as well."
"You let [Wells] know he's the sixth guy and needs to go down and get going to be that guy who gets called up when unfortunate injuries happen," Sveum said.
Wells remembers 2009 when he also began the year at Triple-A Iowa, was 3-0 with a 2.77 ERA, and was called up when Carlos Zambrano was sidelined with a hamstring injury.
"In 2009, the same kind of thing, I went down to Triple-A, started off good and came up and never looked back," Wells said. "We'll just see what happens."