LAS VEGAS » At the worst possible time, a team captain joined “five straight games” as things the Hawaii men’s basketball team has lost.

On Tuesday, the Rainbow Warriors started their desert stay for the Western Athletic Conference tournament with the knowledge that senior guard Zane Johnson, for medical reasons, would not be with them for the game — and they hope, games — that matters most.

Sixth-seeded UH (15-15) opens its final WAC win-or-go-home tourney in dire straights against third-seeded Idaho (18-12) on Thursday.

Three wins in three days would send the ‘Bows to their first NCAA Tournament in 10 years. But UH’s capacity to do that took a huge hit on Monday night, when it was confirmed Johnson would miss the trip. The team’s tri-captain and 3-point marksman is one of three players tied for the team scoring lead at 14.0 points per game.

A weakened Johnson received IV fluids before UH’s 61-60 senior night loss to Utah State on Saturday. He played 28 minutes, scoring 10 points. Cumulative fatigue, however, took its toll afterward.

“The doctor told me (he’s out) two to four weeks,” UH coach Gib Arnold said. “He’s been sick the last few weeks, complaining of being really tired, sore and sick. And we finally had him go in and get tested. He’s got mono. … they were under the impression that he not play or travel or have any kind of contact. He’ll just rest. Obviously we agree with that and support it.”

Mononucleosis is a viral infection that can cause fatigue and a general ill feeling, sometimes lasting for weeks.

But Johnson’s strange late-season saga might not be over after all. At least, as a spectator.

Sophomore center Davis Rozitis, Johnson’s closest friend on the team, hinted that Johnson could make an appearance at the tournament.

“He’s doing all right. Catching some rest. And I think we’ll see him around,” Rozitis said.

Meaning, he might join you here on his own?

“Maybe. Maybe. I cannot confirm or deny that information,” a coy Rozitis said.

Johnson couldn’t be reached for comment.

In any case, the ‘Bows resumed practicing for their first-round matchup against the Vandals without the sets normally run for UH’s career 3-point leader.

“We ran a lot of our stuff through Zane and he’s the main focus point on most of our sets because of his scoring ability,” Arnold said. “You probably have to do it more by committee.”

Some of the role players who will be asked to do so include freshman guard Shaquille Stokes (7.6 ppg), junior forward Hauns Brereton (7.3) and sophomore forward Trevor Wiseman (6.2).

“Shaq’s obviously going to have to step up,” Arnold said. “Trevor’s going to have to step up and play some more minutes, and then we’ll need a big game out of Hauns. He needs to step up, too. He’s older and it’s a time where your older guys have to come and play.”

Brereton, UH’s most efficient 3-point shooter (.377), pledged himself ready to do his part.

“We got a lot of talented pieces on our team, and we’ll just have to step up and make up for what’s left behind,” Brereton said. “He’ll be surely missed, but we gotta play and compete.”

Johnson’s absence will likely mean increased double- and triple-teams on the frontcourt of Joston Thomas and Vander Joaquim. UH’s other co-leaders in scoring have often benefited from Johnson’s presence on the court, and could see heavy zone defense from Idaho.

“We gotta play a lot of team basketball,” Thomas said before Tuesday’s team practice. “Zane’s a great shooter, and he spreads the floor for me and Van to create. Other than that, we gotta play great team basketball and share the ball, and I feel like we’ll be great.”