Advocate file photo by BILL FEIG -- Part of a bullpen that coach Paul Mainieri cobbles to together to form a third starter he calls “Johnny Wholestaff,” Kyle Bouman is the likely starter for LSU’s third game in the Baton Rouge Regional this weekend at Alex Box Stadium.

A year ago, Kyle Bouman was a little known junior college pitcher, dismissed from Wichita State because of alcohol-related incidents.

Just six weeks ago, Bouman entered the preseason as a midweek starter or relief pitcher.

On Saturday, he’ll start LSU’s game at Vanderbilt, coach Paul Mainieri said Monday.

Bouman did enough in his four starts over the season’s first month to earn a spot in the Southeastern Conference weekend starting rotation — at least in the first week.

Bouman is set to start in Game 2 of the Tigers’ conference-opening, top-10 showdown in Nashville against the Commodores (15-2).

Mainieri announced Sunday that true freshman Jared Poché would start Sunday’s game. Poché, Bouman and junior Cody Glenn were competing for the two weekend starting spots behind ace Aaron Nola, LSU’s strike-throwing Friday night starter.

Bouman beat out Glenn, the No. 2/3 starter last season.

“I feel like Kyle Bouman earned it,” Mainieri said. “He went out there and has pitched four times. I think he’s pitched really outstanding baseball all four times.”

Glenn will move into the bullpen and will be ready in a relief role this weekend, the coach said. He expects to use Glenn as a middle reliever type and plans to pitch him against the Commodores, possibly as early as Friday.

Mainieri delivered the news to the players at the school’s academic center Monday, while both were studying.

“I explained to Cody, you can look at this two ways: You lost the battle for the starting job. Or you can look at it as you’re still going to be a vital pitcher on our staff,” Mainieri said. “He’s a team guy and he assured me his attitude would be great.”

Bouman, a Missouri native, went 3-0 and has a 1.46 ERA during his four starts so far.

He’s allowed 18 hits and four earned runs, while striking out 13 and walking one in 24 2/3 innings.

Glenn went 1-1 and has a 4.74 ERA in four starts and one relief appearance. He’s allowed 24 hits and 10 earned runs, while striking out 10 and walking two in 19 innings. He hit four batters.

It came down, Mainieri said, to throwing strikes.

“I think it’s imperative that you throw strikes against Vanderbilt, the type of offensive team that they have,” the coach said. “That’s one thing that Kyle is. He’s a strike-throwing machine.”

Bouman wasn’t expected to be in the competition for a weekend starting spot just a week before preseason practice started in mid-February, but sophomore righty Hunter Newman injured his shoulder. Bouman replaced him in the battle for a starting gig.

Newman, Mainieri said Monday, is out for the season after having shoulder surgery for something similar to a bone spur.

Bouman starred at a Missouri junior college last season after being dismissed from the team at Wichita State in 2012. He admitted to having a drinking problem then. His scholarship was revoked after he crashed his car into a tree while driving drunk.

While at Jefferson College last year he joined a substance abuse class and now says he’s overcome the issue.

“If you told me this about a year a half ago, that I’d be here starting the second game, I’d think you were crazy, honestly,” Bouman said last month.

Glenn struggled in his most recent outing, and Bouman pitched a gem.

Glenn allowed four hits and surrendered a second-inning, two-run homer in the 7-3 win over Purdue on Sunday. He hit two batters, both coming with two outs and two strikes.

After Sunday’s game, Glenn was dejected and disappointed following the game.

Against the same team Saturday, Bouman allowed six hits and two earned runs and struck out five in 6 2/3 innings. He did not walk or hit a batter.

Mainieri said Bouman was “happy” to hear the news of him starting.

“He said, ‘Great. I’ve been working for this. I won’t let you down,’” the coach said.