Nearly five minutes had elapsed in the second half when Lazar Stefanovic took a pass from Skyy Clark in the corner and rose for a three-pointer that extended UCLA’s massive lead in its season opener.

Having barely played to that point, it was Stefanovic’s first shot of the game.

Perhaps nothing better illustrated the Bruins’ offseason makeover than the mainstay from a year ago being relegated to a bit player as part of this new ensemble cast.

UCLA guard Kobe Johnson, right, steals the ball from Rider guard T.J. Weeks Jr. in the first half Monday.

(Gina Ferazzi / Los Angeles Times)

Stefanovic didn’t need to play a starring role given the abundance of talent around him. Kobe Johnson, who took his spot in the starting lineup, was a two-way force with his scoring, passing and active defense. Tyler Bilodeau showed his dazzling offensive skill set with 10 points in a five-minute flash to start the second half. William Kyle III got the crowd going with three blocks.

It was a pleasurable introduction for a new and vastly improved team Monday night at Pauley Pavilion, No. 22 UCLA rolling to an 85-50 victory over Rider.

A year after his team struggled to score on the way to a losing record, Bruins coach Mick Cronin watched several newcomers have little trouble putting the ball in the basket. Bilodeau scored 10 of his 18 points in the second half to lead four players in double-figure scoring. Johnson added 12 points after repeatedly driving for layups, Dylan Andrews made two three-pointers on the way to 14 points and Sebastian Mack added 12 points to go with his trademark grit off the bench.

“We don’t need anybody to try to do too much on this team,” Cronin said, “because if you just get some execution, you get some ball movement, you’ve got guys who can shoot the ball in the basket or go by their man and make a play.”

Stefanovic contributed six points in his 17 minutes, making two three-pointers. Equally important was his willingness to encourage teammates when he wasn’t in the game.

“For him to be able to take a step back and kind of take a different role with this team, it’s just amazing to see him do that,” Johnson said. “He’s got one of the best attitudes I’ve been around. So, that’s really huge for this team for people to unfortunately lose some of their playing time, or some of their minutes, and still have a great attitude, come practice every day, wanting to work and get better. I mean, that’s what’s going to make this team great, people like that.”

UCLA guard Trent Perry is fouled by Rider forward Tank Byard, right, as he’s double- teamed by guard T.J. Weeks Jr. in the first half Monday.

(Gina Ferazzi / Los Angeles Times)

The Bruins won easily on a night when Clark, expected to be one of their leading scorers, got in early foul trouble and scored just three points on one-for-five shooting.

The challenge facing Rider was evident in the opening minutes. Bilodeau stole a pass on the Broncs’ second possession, leading to an Eric Dailey Jr. driving layup for the game’s first points. After the Bruins picked up full-court defensively, Johnson and Andrews eventually trapped Tyriek Weeks, leading to a Johnson steal and another Dailey layup.

Rider forward Tariq Ingraham then threw a cross-court pass out of bounds and Clark soon came up with a steal in the backcourt. Less than four minutes into the game, the Broncs had four turnovers and were trailing 10-3.

UCLA forced 11 of Rider’s 14 turnovers in the first half on the way to a 41-23 advantage before calling off the pressure after halftime to focus on half-court defense. The Bruins finished with 52 deflections — defined as steals, blocks, tipped passes or loose balls collected — to easily exceed the minimum of 40 that Cronin wants in a game.

“I think we showed that we could turn teams over a whole lot,” Johnson said, “and create offense from that.”

T.J. Weeks Jr. scored 15 points to lead Rider, which shot just 32.3% but somewhat offset its inaccuracy with 18 offensive rebounds leading to 13 second-chance points.

“We’ve really got to work on blocking out,” said Cronin, whose team won the rebounding battle, 45-38. “We knew that that was going to be an issue with this team tonight, and for us when Eric Dailey’s out of the game, our rebounding struggles.”

Part of that might have been attributable to Cronin going with his small starting lineup that featured Bilodeau and Dailey as the big men — big, in this case, being relative since they are 6-feet-9 and 6-8, respectively — alongside guards Andrews, Clark and Johnson to combat a team that he knew would spread his players out.

Cronin supersized his lineup later in the half when Aday Mara, a 7-3 sophomore, entered the game and quickly made his gargantuan presence felt. The center blocked three shots — including a mid-range jumper — and was a favorite target of teammates for passes in the paint. Mack found Mara for a dunk and Johnson drove and dished to Mara, leading to a foul on the Broncs as Mara went up for a shot.

One player who did not get into the game until UCLA was ahead by 25 points was Dominick Harris, a transfer from Loyola Marymount who was expected to add three-point shooting after ranking No. 3 in the nation last season by making 44.8% of his shots from long range.

Harris missed his only three-pointer Monday but grabbed four rebounds and played fairly active defense in his seven minutes.

Minutes could be hard to come by no matter a player’s pedigree. Cronin said sophomore forwards Brandon Williams and Devin Williams (no relation) would redshirt and freshman guard Eric Freeny was contemplating a similar fate.

“There are not enough minutes on this team,” Cronin said.

But if Monday was any indication, there could be a lot more wins than last season.