New London — By now, they've earned frequent NCAA baseball tournament qualifier status.

For the fourth time in five seasons, the Mitchell College Mariners are playing in the postseason, opening with Keystone College Thursday in the Harwich (Mass.) Regional at Whitehouse Field. First pitch is scheduled for 4:30 p.m.

The next step for the program is to make a deep run.

They're 2-8 overall in NCAA Division III postseason trips, winning one game in 2016 and one in 2014. Three of those losses are by two runs or less.

They believe they're ready to go where no Mitchell baseball program has gone before.

"The objective is to win (regionals) and get to the college World Series," senior Kyle Hartenstein said. "You get to the tournament a few times and you're kind of testing the waters. ... We've seen what it takes. We've seen it's not something that's unreachable. It's obtainable."

Mitchell (30-8) brings a balanced team to the tournament, featuring a lethal lineup and deep pitching staff. The Mariners are batting .342, with Hartenstein (.408) and senior Garet Griffin (.405), who won the New England Collegiate Conference player of the year award in 2018 and 2017, respectively, leading the charge. The team earned run average is a solid 2.97.

Left-hander Eddie Santiago (6-2, 2.91), a senior from New London, will make his first NCAA tournament start. He's settled into a nice groove, winning his last five starts. He has postseason experience, twice appearing in relief in two previous trips, so he's accustomed to the spotlight. He also enjoys facing high level competition.

"He's taken the ball enough for us," coach Travis Beausoleil said. "The situation shouldn't be a factor for him. He was a Futures League all-star last summer. He's a seasoned vet and that's what you want. ... There's no one else that we trust to take the ball more than him."

Santiago has faith in his teammates behind him.

"Obviously, we're facing some tough competition but this is the most talented team we've had since I've been here," Santiago said.

That's saying a lot.

Mitchell has dominated the NECC in recent years, only failing to capture the league tournament title last season. That painful defeat to Lesley University served as motivation this spring.

This season's team ranks as one of the best in Beausoleil's seven years. Only the 2015 Mariners, who had the misfortune of playing two top five foes in their regional and bowed out in two games, may be better.

"I really thought that team could win a national championship," Beausoleil said. "We were good enough to do it. This team is similar. We've got six or seven arms that we really think we can throw at any time. Offensively, we're a tough lineup to get through three or four times.

"... It's an opportunity to really do something special this weekend."

Winning the opener is the key to surviving deep into any double elimination tournament. The sixth-seeded Mariners are facing a major roadblock in No. 3 Keystone (32-10), making its 10th straight NCAA appearance. The Giants have a powerful lineup, belting 30 home runs this season.

"They won our region two years ago and went on to lose in the championship in the World Series," Santiago said. "They're very talented. Should be fun, for sure."

Odds of winning will increase for the Mariners if they can avoid giving up a big inning and can limit mistakes and free passes.

They also need their veterans to deliver in the clutch. All but one starter — sophomore Jeremy Santos of New London — is an upperclassmen.

It's also helpful to have some players with postseason experience on the roster.

Hartenstein, a four-year starter at second base, will be playing in his sixth NCAA game. He's batted .368 (7-for-19) with two RBI against tournament competition. Griffin, a shortstop, senior outfielder Jack Finnegan and junior catcher Marcus Melendez all started three games in 2016 while junior Brian Ricker made two relief appearances totaling one scoreless inning.

"Being seasoned with it, you know what you're going into," Hartenstein said. "You know every team there is going to be legit and we have to play our 'A' game."

Griffin isn't worried about the Mariners being intimidated by their higher rated opponents. He believes the pressure is off after they accomplished their season-long mission to win the NECC Championship and return to the regionals.

Now they can just go out and play their game while showcasing their program.

"It's our turn to get some respect," Griffin said. "We've been there. We've faced teams like this in regionals. We can play with those guys. It's a matter of going out and doing it now and taking care of business. The respect is something that we feel that we deserve, so we've got to go get it."

g.keefe@theday.com