Locke took the mound as scheduled for Triple-A Indianapolis in Thursday night's game in Charlotte, meaning he would not be available to start on Monday. Cumpton, conversely, made his last start for the Indians on Tuesday, meaning he could step into Rodriguez's spot with only one extra day of rest.
However, not even these clues guarantee Cumpton's selection. Locke may simply be getting in some work to keep sharp, since otherwise he'd be asked to face the Mets with 10 days between starts.
In early organizational talks about the rotation's future, both pitchers had plenty of backers.
"The camp is as split as you can get," Huntington said early Thursday afternoon. "You heard, 'Brandon is throwing the ball great, doing things we love,' and, 'Jeff is back. The velocity has been better than a year ago, the breaking ball, changeup and command are all good.' So it's a really challenging decision."
The confidence in both pitchers made a quick call on Rodriguez easier. The lefty was designated about 19 hours after delivering the last pitch of his 1 2/3-inning start on Wednesday against Baltimore.
"We have two guys we feel completely comfortable about coming in and taking that spot," Huntington said. "Whether it's Brandon or Jeff, he will give us a legitimate opportunity to win the game. We didn't have that feeling with Wandy."
Either would have been a hot choice.
Locke spun one-hit ball for seven innings in his last start on Friday against Pawtucket. Those seven shutout innings lowered his ERA to 3.82.
Cumpton has been even more consistently impressive, sporting a record of 4-1 with a 1.35 ERA. Most recently, on Tuesday, he allowed a run and five hits in eight innings against Gwinnett. Cumpton also boasts the more successful recent big league experience. Including his two starts this season for the Bucs, he has a WHIP of 0.99 in his first eight Major League appearances.
Tom Singer is a reporter for MLB.com and writes an MLBlog Change for a Nickel. He can also be found on Twitter @Tom_Singer. Stephen Pianovich is an associate reporter for MLB.com This story was not subject to the approval of Major League Baseball or its clubs.