It already had the makings of the toughest test of the season.

With the added blow of star center Osun Osunniyi being sidelined with concussion-like symptoms after taking an elbow to the head during the first half of Wednesday’s win over UMass, the St. Bonaventure men’s basketball team’s road matchup with VCU had the potential to be disastrous.

And almost right away, that’s what it was.

Much like last year, the Bonnies struggled to score against VCU’s pressuring, trap-heavy defense. Just like last February, they couldn’t stop the Rams, who were also without a key player — all-conference point guard Marcus Evans — from relentlessly attacking at the other end.

The result was essentially a carbon copy of last winter’s 85-55 loss in the Reilly Center, with Bona bowing to a better VCU team, 91-63, before a crowd of 7,367 inside the Siegel Center on Saturday afternoon.

Bona (12-6, 4-1) had entered the day on a high, winning its first four Atlantic 10 games to match its best start in program history and checking in as one of the conference’s three remaining unbeaten teams.

Just like that, however, it was handed its worst loss of the season, and only four days ahead of what figures to be an even more daunting challenge, depending on the availability of Osunniyi: Wednesday’s game against No. 13 Dayton inside UD Arena.

“Early on, we missed a lot of layups, open jump shots and then it just snowballed on us,” said coach Mark Schmidt, whose team trailed 11-8 before VCU went on a furious 18-0 run to seize control midway through the first half.

“We didn’t do a good job defensively. They took us off the bounce; they were going downhill all night. Part of it was our offense, we couldn’t score so now they’re out in the open court, and the game was over at halftime.”

The numbers were ugly, particularly over the first 20 minutes.

With VCU keying on leading scorer Kyle Lofton, and finding quality shots hard to come by, Bona shot just 29 percent in the first half, including 1-for-8 from 3-point range, and had just 12 points through the first 14:20.

In Evans’ absence, freshman Nah’Shon Hyland stepped up, scoring 17 first-half points (21 for the game) on 6-for-8 shooting, including five 3-pointers that helped the Rams grab an early 20-point lead and extend it to 52-24 at the break. And with Osunniyi sidelined and backup Amadi Ikpeze quickly limited by foul trouble, the Bonnies had no answer for VCU big man Marcus Santos-Silva, who went for 11 points and seven rebounds in the first half en route to 17 and 11 for the game.

For the second-straight year, Bona hung with the Rams (13-5, 3-2) in the second half, playing to a 39-39 tie. But by that point, the damage had been done.

“Give our guys credit, we fought in the second half, we didn’t give in,” Schmidt said. “But that’s a good team, and when you don’t score and you’re having trouble scoring and they’re going downhill on you, you’re in for a long day.”

As it can often be against the Rams, who thrive at turning opponents over, this wasn’t about giveaways; Bona committed just nine turnovers, an excellent number against a team that had been forcing 19 per game.

This was about all the missed shots that allowed VCU to get going in transition and find its groove offensively, both from 3-point range, where it went 9-for-22, and in the paint, where it outscored Bona, 48-30.

“If you told me we were only going to turn it over nine times, I’d be like, ‘we have a shot,’” Schmidt said. “We were missing so many baby shots, and then going down at the other end and Hyland came off hot at the beginning of the game; they were 7-of-12 (from 3s) in the first half, and that was one of their weaknesses.”

He added: “We had a hard time keeping them in front. Our ball screen defense wasn’t good, so consequently, they were getting the ball into the paint and getting some easy shots.”

Justin Winston scored 17 points while Jaren English added 15 for the Bonnies, whose brightest stretch came early in the second half, when they outscored the Rams 12-6 to start the period. Lofton and Dominick Welch were limited to six and seven points, respectively, on 5-of-17 shooting.

“We did a decent job of getting the ball into the middle,” Schmidt said of his team’s ability to handle VCU’s pressure. “We took care of the ball, for the most part; their press … got us out of rhythm at times, and they took the ball out of Kyle’s hands. But then somebody else has to make a play.

“At times, we had that. In the second half, we played better, but the game was over at halftime.”

Bona fell to 1-5 on the year when Osunniyi sits (including the season-opener against Ohio, when he played just 11 minutes), another indication of just how instrumental he is in the team’s success.

And now, with or without Osunniyi, it gets no easier for Bona, which will take on one of the best teams in the country on Wednesday before returning home to play a Rhode Island that won in the Siegel Center last week.

“We gotta go back to work, and we have another tough road game (against Dayton),” Schmidt noted. “We understand this is the tough stretch of the season against the three ‘quote’ marquee teams, so we gotta back and we gotta get better.”