There is a fine line that separates teams from winning and losing, and Kenosha Unified hockey coach Steve Carlson doesn’t like which side of the line his team has resided on this season.

The divide relates to preparation and mental attitude, and Carlson offered a scathing review after the Thunder lost 5-3 to Fond du Lac/St. Mary’s Springs in Tuesday’s non-conference game at the Kenosha Ice Arena.

In what has been a season-long problem, the Thunder (8-6) fell behind early and were forced into catch-up mode.

“The first period costs us every game,” Carlson said. “... You have to be mentally prepared to play, and they’re not ready to play. You can tell them all you want how to prepare for a game, what you have to do to play the game. If they’re not willing to do it, I can’t go out there and play the game for them.

“They play their style, their way and they get behind and now we have to make comebacks constantly all year. ... We’re an ugly team. We’re a grinding team. We’re not going to score five, six, seven goals to get us out of trouble, so we have to play tight defense. They don’t like playing defense.”

Kenosha took a 1-0 lead 1½ minutes in as Devin Dorsey gained control of the puck near center-ice, skated down the right side and passed to his left to T.C. Trainor, who was skating parallel to him and deposited a shot from close range into the corner of the net.

It started going south for Kenosha after that, though, as the Ledgers (8-5) — who have won eight of their last nine since an 0-4 start — scored three times, including twice on rebounds.

Fond du Lac/St. Mary’s Springs went ahead 4-1 four minutes into the second period on Chris Meyer’s power play goal.

Kenosha cut the deficit in half on Matt Hill’s top-shelf shot from the slot but wasted prime scoring opportunities in the final six minutes of the period.

The Thunder didn’t attempt a shot on goal after a Fond du Lac/St. Mary’s interference penalty put them in the power play, and it got even worse for Kenosha when it couldn’t take advantage of a 5-on-3 following two Ledgers’ tripping penalties.

The Thunder fired at least seven shots in the final 2:27 of the second but came up empty each time.

“We work the power play every day. I don’t know what happens in a game,” Carlson said. “They go brain dead or whatever. It works in practice, they move the puck.

“... Once the game comes, they forget everything. It’s unfortunate we have a couple players that work hard, give it (maximum) effort every time on the ice and unfortunately we have a bunch of players that aren’t willing to sacrifice to win. They’re out there just for a day of figure skating or public skating.”

The Thunder did capitalize on another 5-on-3 power play when Cole Thompson scored from the right wing with slightly more than 11 minutes remaining. And it appeared as if Kenosha tied it at 4-4 with 8:34 left when Ian Dart scored a few seconds after a faceoff in front of the Ledgers’ net.

But the referees disallowed the goal, ruling Dart had batted the puck in with his hand instead of his stick.

Jack Schultz scored his second goal, on another rebound, to put the Ledgers ahead 5-3 with two minutes left. Kenosha pulled goalie Nick Hollendonner (26 saves) with 55 seconds left but didn’t get off any shots on goal after that.

The Thunder play another home game 7 p.m. Thursday against Waukesha Catholic Memorial/Milwaukee Pius XI (13-2-1), which is ranked No. 6 in the state in the latest Wisconsin Prep Hockey poll and No. 1 in the Milwaukee Journal Sentinel’s area poll.

At 4-0, Catholic Memorial/Pius shares first place in the Classic Eight Conference with Hartland Arrowhead, a half-game ahead of Kenosha and Kettle Moraine/Mukwonago (both 4-1).

Carlson said he is hoping his players make a drastic improvement in their mental preparation and attitude by Thursday night.

“If they play like this against that team, oh, boy,” he said. “Oh, boy, we’re in trouble.”