The season was slowing slipping away for the Mansfield High boys’ basketball team. The Hornets were locked up, 53-all, with Catholic Memorial entering the fourth quarter of Tuesday’s Division 1 South final in Newton. But a late CM run left the Hornets trailing by double digits in the closing minutes.

The score mattered little to Christian Weber, a junior point guard for Mansfield. Digging in defensively, he dove forward and tipped the ball out of bounds, crashing to the floor.

The game was out of reach, but Weber left everything on the floor, offering a glimpse of what is in store for his final season for the black & green.

Weber is just one of a number of non-seniors who have stepped forward to play critical roles for tournament-bound teams.

“As we’ve gotten into the second half of the year, he’s really been the difference maker,’’ said Mansfield High coach Mike Vaughan, who opened this season minus graduates Mike Boen and Ryan Boulter, a Globe All-Scholastic, from last year’s squad.

A year ago as a freshman, Noah Fernandes helped direct Old Rochester to the Division 3 state title. He transferred to Tabor Academy, re-classified as a freshman, and stepped right in at the point at the Marion prep school.

“At the beginning it was real tough,’’ said Fernandes, who averaged 15 points per game and earned honorable mention honors in NEPSAC Class A. “When I came in, I don’t think they would’ve thought I was going to start.’’

Tabor coach Chris Millette has traditionally built his attack around a post player, most recently with Plymouth’s Jesse Bunting, now a 6-foot-8 freshman at Fordham.

“We knew our identity was going to change to a guard-oriented team,’’ said Millette.

Fernandes triggered the transition, averaging fewer than two turnovers per game for a Tabor squad that took care of the ball better than any of Millette’s previous six teams.

With the departure of Fernandes, in addition to the graduation of two more starters, guard Jordan Menard and Ryan Beatty, Old Rochester coach rebuilt his team around Matt Valles, a 6-foot-5 junior.

“We wanted to get Matt his touches,’’ said Carvalho. “He’s been a focal point.’’

Valles (13 points, eight rebounds per game) is a skilled big: dominant on the boards with a feathery touch around the basket. His ability to flick outlet passes allowed the Bulldogs to play faster.

“Once we’re rebounding, we can get out on in transition,’’ Carvalho said. “He can rim-run. He’s also a nice trailer, shooting that 15- to 17-foot jumper.

“He’s got the big-game experience. Now he’s just going to take it to the next level,’’ Carvalho said.

At Rockland, Fred Damon started reloaded with the graduation of 10 seniors. Somewhat surprisingly, the Bulldogs bounced back with a 19-3 season following the lead of senior Stephen Norris (19 ppg.) and the emergence of juniors Jakigh Marcelin and Jake Crawford.

“It’s definitely something the kids were aware of: that no one was paying attention to us at all,’’ Damon said. “I think it drives them and motivates them.’’

Marcelin, a reserve last season, averaged 14 points and 10 rebounds per game, showcasing skills to play play point forward as well as playing down low.

“He’s really, really elevated his game,’’ Damon said. “He’s added the ball-handling and beating people off the ball this year.’’

Marcelin, who played AAU ball with the South Shore Wolfpack, focused on his ballhandling during the offseason. Crawford moved from the end of the bench to the starting lineup, averaging 11 points per game.

Damon says his approach with Crawford was “throwing him into the heat of the kitchen and seeing what he’s all about.’’

“We told him from the get-go, we need you to do A, B and C and he responded,’’ Damon said. Adding a third scorer made Rockland tougher to defend.

“I feel like I had to step up a little more,’’ Crawford said.

“Last year, it was every article saying; ‘What’s Mansfield going to do without Bolter and Boen?’’’ Vaughan recalled.

Weber acknowledged he struggled at first with the responsibility of running the offense. But he trusted his preparation, and it paid off. The junior averaged 4.5 assists to just 1.5 turnovers, and was able to get the ball to leading scorers Sam Goldberg and Matt Ehrlich .

“Last year I had a tough time handling the ball at times and I figured the one thing I could do was improve my ball handling and ball security,’’ Weber said.

He also stepped forward as a leader. He made clutch plays. And though not a natural scorer, he upped his average to 8 points per game in the second half of the season.

“He’s probably one of the best vocal leaders I’ve played with,’’ said junior forward Phil Vigeant.

At Mansfield, Vaughan said he and his young floor leader had to establish common ground to foster growth.

“Since we’ve done that he’s come a little bit my way and I’ve allowed him to go his way. I think the compromise has worked for us,’’ said the coach.

“He’s been the guy we’ve silently relied on.’’

Matt MacCormack can be reached at matt.maccormack@globe.com.