LSU’s bullpen roles are being assigned, but it’s a developing situation as the Tigers prepare to open the season against Maryland on Friday night in Alex Box Stadium.

Coach Paul Mainieri appointed senior left-hander Chris Cotton as the closest thing to a designated closer Monday, but protecting ninth-inning leads will be a shared responsibility.

If Cotton, who’s also scheduled to be the Sunday starter, closes Friday, then junior right-hander Kurt McCune will be next in line if a closer is needed Saturday.

Senior left-hander Brent Bonvillain will have a hybrid role similar to Cotton’s, senior right-hander Joey Bourgeois will be a key set-up man, and junior right-hander Nick Rumbelow will figure into the equation in a week or two when he returns from a strained oblique muscle.

That takes care of the primary late-inning roles, at least early on.

“Cotton can handle any role,” Mainieri said Monday. “He has the unique qualities you look for in a quality closer. He’s a strike-throwing machine; he can throw three pitches for strikes; and as a left-hander, he can stop the running game better. He has experience and poise.

“What is there not to like? He has everything to be a really quality (Southeastern Conference) pitcher.”

Cotton, 7-0 with a 1.59 earned run average as a versatile reliever last season, started in summer league play to see how he would respond to extended outings, and he passed the test. But Mainieri didn’t want to lose his value as a reliever, so he placed him in a role that Louis Coleman and Jared Bradford excelled at on previous Mainieri teams.

“Last year, I had a lot of fun being a reliever that could come into any situation,” Cotton said. “I like being able throw in any situation that the team needs me.”

Cotton’s workload will have a bearing on how Bonvillain is used. If Cotton is unavailable Sunday, Bonvillain will start. Otherwise Bonvillain will be the midweek starter, at least during the pre-SEC schedule, and also be available to relieve.

“Cotton and I are pretty much the same pitcher,” said Bonvillain, who started in high school and junior college before moving to the bullpen last season. “We’re sort of interchangeable.”

Left-hander Cody Glenn will start out splitting time between the bullpen and starting midweek when Bonvillain is not available.

McCune started as a freshman two years ago and began last season as the Sunday starter before moving to the bullpen after freshman Aaron Nola emerged as a starter. McCune added a splitter to his repertoire of pitches during the offseason, which Mainieri said has made him more effective.

Mainieri had McCune throw one inning each in scrimmages Friday and Saturday and said McCune was at his sharpest Saturday, showing that he’s getting accustomed to short relief.

“I can use the splitter as an out pitch,” McCune said. “I can use it as a changeup. I’ve had pretty good command with it.”

Mainieri said Bourgeois has been so consistent as a one-inning set-up guy that he’s reluctant to “expand his role” into closing and disrupt him, though it’s tempting.

“Whenever he calls my name, I know I’m going to be ready,” Bourgeois said. “It doesn’t matter what role I’m in.”

Rumbelow closed at the start of last season before suffering a hamstring injury and seeing Nick Goody grab the closer’s role and get a team-high 11 saves. Goody signed with the New York Yankees, leaving the closer’s role up for grabs.

LSU catcher Ty Ross said he had “the privilege” of catching Rumbelow last summer as Rumbelow earned all-star honors in the Cape Cod League.

“He was outstanding,” Ross said. “He just pitched lights out, strikeout after strikeout. That curveball was nasty, the fastball was heavy.”

Pitching coach Alan Dunn said the Tigers “shut down” Rumbelow in the fall because he had been pitching almost nonstop since high school.

“I think that helped him refresh his body and his mind,” Dunn said. “You talk about a competitor. This kid wants the ball in whatever situation you want to give it to him in. You know what you’re going to get from him every time out. He’s going to give you what he has. He’s going to be a big part of our bullpen.”

Six newcomers — right-handers Will LaMarche, Hunter Newman, Russell Reynolds, Mitchell Sewald and Taylor Butler and left-hander Hunter Devall — and senior right-hander Kevin Berry fill out the bullpen.

“Just as important as the closing role is those sixth, seventh, eighth innings,” Dunn said. “You’ve got to get to the ninth. Those middle innings are huge.”

Once SEC play begins March 15 at Mississippi State, the midweek games could become vehicles for tuning up the bullpen for the weekend.

“(Dunn) and I both came to the realization (last season) that guys were pitching better on the weekend, getting that little outing in the middle of the week,” Mainieri said. “There were several times I used like nine pitchers in a game, and sometimes it was just to get one out. But it was just to get the guy back out on the mound to face a hitter even, if it was just one batter. It kept him sharp for when we went into the weekend.”