With the temperature in the high 80s on an August morning last year, Solo Vaipulu wanted to make sure the Hawaii football coaches had not made a heat-of-the-moment decision.

Vaipulu was assigned to the Rainbow Warriors’ No. 1 offensive line, but was the depth chart written in chalk?

“I wanted to make sure I stayed there for another week,” Vaipulu said. When it appeared he had secured the right guard’s job, “I finally told my parents. They were pretty happy.”

Offensive line coach Mark Weber was equally pleased to have a key blocker for his starting unit.

“There were days we had six (offensive linemen) out here in (last year’s) spring practice,” Weber recalled.

It was early in the 2018 training camp, after practice reps and video analysis, Weber determined two freshmen — Vaipulu and left tackle Ilm Manning — were deserving of berths on the front line.

“I’m going to play the best guys,” Weber said. “They were two of the five best.”

Vaipulu and Manning started all 14 games last season. In more than 950 plays, including 545 pass attempts, neither was assessed a holding penalty. In 13 regular-season games, Manning’s lone penalty was for being too far downfield during a pass to slotback John Ursua.

Weber was hired at UH in January 2018, a few weeks after Manning had made a written commitment to join the Warriors.

“When I watched film on him, I thought, ‘There’s a tremendous athlete with great hips and great athletic ability,’” Weber said.

Weber said Manning’s ability to make adjustments counters defenders with multiple pass-rushing tools.

“He’s so athletic that when he gets into trouble, he can recover,” Weber said.

Apollo High (Ariz.) assistant coach Aaron Walls saw those same qualities when he convinced Manning to switch from defense to offense for his senior season. Manning excelled as a 250-pound blocker, drawing interest from the Warriors.

“When I got here, I did a lot of studying of film and going over the plays,” Manning said. “That’s what helped prepare me.”

A mid-term exam came against Wyoming defensive end Carl Granderson.

“That’s when I realized, ‘Oh, my gosh, this is some serious stuff,’” Manning said. “He was real tough and real strong. He was pushing my limits to become better.”

Manning made a key block on Chevan Cordeiro’s game-winning scoring pass against Wyoming. Manning finished the season at 270 pounds.

Vaipulu was quick to impress with what Weber termed “good feet and a great football IQ.” Weber has praised Vaipulu for “being cool under pressure. He’s a very fast learner. And he’s got something to him. He’s tough.”

Vaipulu, a graduate of Corona Centennial High (Calif.), said he and Manning did not harbor expectations of being first-year starters.

“We came out here with the mind-set we were trying to grind,” Vaipulu said. “Fortunately, we were both blessed to be named starters.”

At the end of the 2018 season, Vaipulu weighed 315 pounds. He pledged to improve his fitness during the eight-week conditioning program.

“I felt I was out of shape a little bit,” he said. “I decided to lose more weight and get healthier.”

He entered this past week’s spring training at 288 pounds. The offensive line’s depth also is healthier. There are 17 offensive linemen on the spring roster, including 12 on scholarship.