"I don't think they view it like that, and I don't blame them," manager Terry Francona said. "They're competing. But, we have to try to balance knowing that maybe we really like our starters, and we want to see them pitch, and you have to be prepared that, if somebody goes down, it doesn't derail your season. That's a really difficult, fine-line for a general manager to try to accomplish."
As things currently stand, Cleveland's rotation projects to include Opening Day starter Justin Masterson, followed by Corey Kluber and Zach McAllister. Danny Salazar is also a virtual lock to make the staff, but he will likely be slotted into the fifth spot. The last job is up for grabs among Carlos Carrasco (out of options), Josh Tomlin and Aaron Harang. Prospect Trevor Bauer also has an outside shot at that spot.
Marcum, 32, is in camp as a non-roster invitee after undergoing surgery to alleviate thoracic outlet syndrome in July. The right-hander went 1-10 with a 5.29 ERA in 14 games with the Mets last season, but is 58-46 with a 3.88 ERA in 188 career games in the Majors between stints with the Blue Jays, Brewers and Mets.
Most of Cleveland's starters have been built up to four or five innings by now, while Marcum is scheduled to throw his second live batting practice session of the spring on Tuesday. Francona indicated that a simulated game might be the next step.
"Shaun is coming back from some injuries," Francona said. "So, we knew he was going to be behind everybody else. When you get into the volume of Spring Training -- not just doing your throwing, but doing your [fielding], your side days -- we let the trainers, [the pitchers'] arms, themselves dictate the schedule.
"We've kind of gone on him, on how best to get him ready to pitch. If that takes a week, two weeks longer than we anticipated, that's really not a big deal."
Jordan Bastian is a reporter for MLB.com. Read his blog, Major League Bastian, and follow him on Twitter @MLBastian. This story was not subject to the approval of Major League Baseball or its clubs.