MINNEAPOLIS -- As they prepare to enter a stretch beginning Tuesday in which they will play 20 games without a day off, the Astros have discussed using a six-man pitching rotation, manager Dusty Baker said Saturday. That would allow the Astros to slot Lance McCullers Jr. back into the rotation when he comes off the injured list without bumping anyone from the rotation.

McCullers, who has been on the injured list since May 26 with right shoulder soreness, threw 64 pitches in four innings in a Minor League rehab start Thursday at Triple-A Sugar Land and proclaimed afterwards he was ready to rejoin the Houston rotation. The Astros have been getting great starting pitching, even with McCullers out.

Starters Zack Greinke, José Urquidy, Framber Valdez, Jake Odorizzi and Luis Garcia combined for a 2.97 ERA in the team’s previous 15 games entering Saturday, so finding the right arm to move to the bullpen will be tricky.

Valdez is 2-0 with a 1.47 ERA in his first three starts of the season after missing the first two months with a broken finger; Garcia had won five consecutive starts entering Saturday; Greinke is 4-1 with a 3.07 ERA in his last six starts; and Urquidy has a 5.19 ERA in three starts since coming off the IL, but held the Twins to three runs in seven innings Friday.

Then there’s Odorizzi, who has a 6.75 ERA in six starts, but showed some progress in his previous start Wednesday by allowing three runs in five innings in Boston.

Garcia has filled in for injured pitchers all season and has perhaps been the Astros' best starter this season. Moving him to the bullpen remains an option, but he’s pitched well enough to keep getting starts. Greinke and Valdez are rotation anchors who will remain in their roles. That leaves Urquidy and Odorizzi as candidates to go to the 'pen, but Odorizzi may not be a fit because he has been a starter his entire career.

The Astros moved starter Cristian Javier to the bullpen last month and he threw four scoreless innings in relief Wednesday, which put him out of action for a few days.

The bottom line is the Astros are about to have a surplus of starting pitching and could use some help in their beleaguered bullpen. Which way will they go? We should find out next week.