With Cole Hamels coming to the North Side, the Chicago Cubs will have to make some changes to their pitching rotation, and on Saturday they revealed their odd man out.

According to manager Joe Maddon, Tyler Chatwood will move to the bullpen in a long relief role when Hamels is added to the big league roster next week.

Chatwood, who leads the big leagues in walks and has a 4-5 record and a 4.98 ERA this season, will be available in a long relief role beginning on Tuesday when the Cubs visit the Pittsburgh Pirates.

Mike Montgomery, who ascended to the rotation when Yu Darvish went on the disabled list, will remain in the five-man rotation for the time being, Maddon said.

Hamels is expected to make his Cubs debut on Wednesday against the Pirates at PNC Park. He will be preceded in the rotation by Jon Lester, who will throw on Tuesday after the team has a day off.