In return for Hammel, Tampa Bay received Double-A right-hander Aneury Rodriguez.
Hammel went 4-4 with a 4.60 ERA pitching mostly out of the Rays' bullpen during the 2008 season.
"It's a new start, and I'm ready to go," said Hammel by telephone on Sunday afternoon. "I really didn't have a role [with the Rays] -- I bounced back and forth. [The Rockies] traded for me, so they must have something planned for me."
At the beginning of Spring Training, Tampa Bay had four legitimate candidates for the rotation's No. 5 spot: Hammel, Niemann, David Price and Mitch Talbot. Niemann is now the last one standing.
"It feels great [to earn the job]," said Niemann, who was scheduled to join the Rays in Boston on Sunday night. "The whole camp, you just looked down the line and saw so much talent. It's probably not going to sink in until tomorrow."
Hammel, Niemann and Cormier were all out of Minor League options, meaning if they did not make the 25-man roster, Tampa Bay would have had to expose them to waivers. Given their talent level, any one of the three would likely have been claimed by another team.
"So we just had to make our Sophie's choice right there, and we chose that particular route." Rays manager Joe Maddon said.
Hammel, 26, came up through the organization after Tampa Bay selected him in the 10th round of the 2002 First-Year Player Draft. He said he will miss the club.
"I'll always remember my days with the Rays as good days," Hammel said. "It was fun. I'll absolutely miss the guys. I learned a lot with the organization, and I'm appreciative they gave me an opportunity to pitch in the Major Leagues.
"It is a bummer I won't get to see the guys to tell them good-bye, but I can't wait to meet my new teammates, either."
Hammel has a 7-15 record with a 5.90 ERA and two saves in three Major League seasons.
Contrary to the rumor mill, Rays executive vice president of baseball operations Andrew Friedman has had a good idea about his club's intentions for some time.
"Colorado was aggressive about Jason, and I felt early on like that was what we were going to end up doing," Friedman said. "It just took some time to work through, but we weren't having as many conversations about different things as people reported. In fact, a couple of weeks ago, I felt confident that this was the move that was going to happen. So there wasn't a whole lot going on, as people suggested."
Niemann, 26, was selected by Tampa Bay with the fourth pick of the 2004 Draft, but the 6-foot-9, 260-pound right-hander has been slowed by injuries and difficulties with his mechanics. Friedman explained why the Rays went with Niemann, touting the right-hander's improvement in pitching down with his fastball and his commanding his breaking ball, which Friedman called "exceptional this spring."
"He has really taken the ball pretty consistently the last couple of years and has continued to get better," Friedman said. "You see it a lot with taller pitchers, that it takes them a little longer to achieve success on a consistent basis. A lot of it has to do with the size and the timing and the long levers, and the delivery is something we've seen a marked improvement in the last couple of years."
Niemann could still end up in the bullpen, too -- a scenario Friedman did not rule out.
"When you have the depth we have as we sit here today, things can change very quickly," Friedman said. "But we have [enough] very talented arms that how we fill one through 12 in our pitching staff remains to be determined. But for us, it's about having quality, and we feel we have that."
Cormier's presence on the team also affected the decision. The Rays need a long man, and Cormier had a nice spring, which validated what Tampa Bay scouts thought of the right-hander last season and enticed the club to sign him as a free agent.
"We feel like Lance fits in very well for us and can pitch multiple innings and can also pitch an inning at a time," Friedman said. "And [he can do] something that will really help our bullpen -- he keeps the ball on the ground [and has had] a lot of success against left-handed hitters. As we were looking at him -- trying to match up our seven bullpen guys -- we felt like he fit us very well."
Baseball America ranked Rodriguez as the Rockies' No. 16 prospect after he went 9-10 with a 3.74 ERA, 139 strikeouts and 40 walks in 156 innings at Class A Modesto in 2008. He was scheduled to start the season at Double-A Tulsa but now will be rerouted to Double-A Montgomery.
"He's had tremendous success," Friedman said. "He misses bats, doesn't walk guys. We think he'll have an above-average curveball and a real good feel for pitching -- a real good delivery. He has clean arm action. There are a lot of things we look for and feel like he has a chance to have success in the Major Leagues.
"He just adds to the depth that we have in the Minor League system with arms."