Outside linebacker David Manoa suffered what appeared to be a serious injury to his left leg during the University of Hawaii football team’s spring practice on Saturday at the school’s grass practice field.

The injury occurred when Manoa was engaged in a clean block with a teammate.

"It wasn’t anybody’s fault," head coach Norm Chow said.

Manoa was on the ground for about 12 minutes. After an ambulance arrived, the Rainbow Warriors gathered in support before Manoa was taken to a hospital.

Chow said he was hopeful "everything will be all right" and that summoning the ambulance was a "cautious" measure.

Manoa is a 6-foot-3, 210-pound linebacker from San Mateo, Calif. He redshirted as a freshman in 2013, but is projected to be in the rotation at outside linebacker in the Warriors’ newly implemented 3-4 defensive scheme.

Offense clicking early

The offense did well in the Warriors’ first spring practice using shoulder pads.

In situational 11-on-11 drills — defenders were allowed to make wrap-up "tackles" but not take down ball-carriers — the offense converted eight of 10 third-down plays.

Chow said the offense was expected to play well against the new defensive system. Kevin Clune, who was hired as defensive coordinator in January, has changed the base front from a 4-3 look to a 3-4 alignment. For Saturday’s practice, Clune added another defensive coverage during a walk-through session.

"We’ve had to really cram to get some things in," Clune said. "But, hey, the kids did a pretty good job. There were a bunch of mistakes in there, but today was a step forward. The effort is getting a little better. Their football smarts are better. I’m happy."

Ikaika Woolsey, Jeremy Higgins and Taylor Graham rotated at quarterback. Each is in his third UH spring training.

"You would hope the offense would look better," Chow said. "But when the defense catches up, it’s going to be tough."

Woolsey, who has been taking the first snap of each drill, displayed his elusiveness when he evaded a manhunt and then fired to slotback Quinton Pedroza along the left sideline.

"I know where my boys are going to be on the field," Woolsey said. "I know I have a good arm, but when it comes down to it, I can make plays (by scrambling). When that happens, and the defense comes up, I can throw it over the top to receivers."

During the offseason, the three quarterbacks ran the players-only workouts, sometimes twice a day. Woolsey said they used the same plays that the Warriors are now using in spring ball.

"It was just the boys, putting in the work and forming that bond," Woolsey said. "You could tell we’re flourishing on the field because we know what we’re doing. Coach (Chow) always says football is easy when you know what you’re doing. You can just go out there and have fun and fly around."

The Warriors are off Sunday. Their fourth of 15 spring practices is Monday morning.