So when he got his chance in American's last regional round-robin game, he made the most of it.
Clarkin, Fairfield's No. 4 pitcher, surrendered just five hits, striking out five in a complete-game effort as Fairfield routed Wellesley, Mass., 9-2 at Breen Field.
"They have some good hitters," Clarkin said. "I just tried to locate and throw strikes."
American catcher Biagio Paoletta was 3-for-4 with six RBIs, raising his regional average to .643.
"He's a big-game player," American manager Bill Meury said of Paoletta. "He doesn't let the situation dictate his approach."
Ryan Meury was 2-for-3 with three runs scored and Chris Meyers homered as Fairfield improved to 17-1 this summer. Clarkin also helped his own cause, going 1-for-1 with two walks and three runs scored.
"I just tried to put the ball in play and hit it hard," Clarkin said.
Fairfield clinched the No. 1 seed in the single-elimination semifinals with a 4-0 record. American will play fourth-seeded South Burlington, Vt., Thursday at 1 p.m. Fairfield beat Vermont 17-1 in the teams' first meeting on Saturday night.
"I think any team here would want to be the No. 1 seed," Meury said. "All the teams are very good ... It's all a clean slate going forward, and I don't think the teams who are Nos. 2, 3, 4 really care the fact that we're the No. 1."
Clarkin -- making his first start this summer and his first appearance since July 22 -- changed speeds masterfully, getting nine of his 18 outs on ground balls.
"Matty's pitched some big games for the last three years for us," Meury said. "He hasn't been out there for a while, and it was a testament to him that he was able to go out there and throw like he had for the last month and a half."
Kaeden Bentley's one-out home run in the top of the fourth was the lone earned run Clarkin allowed.
Paoletta gave him some run support in the second when, with two outs, he laced the first pitch of his at-bat to the right-center field gap, emptying the loaded bases for a triple and putting Fairfield up 3-0.
"It was pretty important," Paoletta said. "We wanted to start out with a bang."
After Meyers homered to lead off the fourth, Clarkin and Meury followed with singles and Paoletta's RBI groundout made it 5-1. Will Lucas followed with an RBI single, lifting American's lead to 6-1.
Ryan Meury's RBI single in the fifth gave American a 7-1 lead and Paoletta followed, capping his big offensive day, with a two-run single.
"I was just trying to make sure I make contact," Paoletta said.
WELLESLEY, MASS. 000 101--2 5 1
FAIRFIELD AMERICAN 030 33x--9 11 2
Records: Massachusetts 2-2; Fairfield American 4-0. Batteries: M--Matthew Simon (L, 0-1), Ryan Murrey (4) and T. J. Maley; FA--Matty Clarkin (W, 1-0) and Biagio Paoletta. Home runs: M--Kaeden Bentley; FA--Chris Meyers. Time of game: 1:28.