INDIANAPOLIS » Top draft prospect Star Lotulelei will undergo more extensive heart tests when he returns to Utah.

Doctors at the NFL’s annual scouting combine in Indianapolis found the star defensive tackle and likely high pick has a heart condition, Lotulelei’s agent, Bruce Tollner, confirmed in a series of emails with The Associated Press today.

Tollner said Lotulelei would not take questions regarding the diagnosis yet. But the 6-foot-2, 311-pound defensive tackle still plans to do a full workout in front of scouts at his regularly scheduled Pro Day on March 20. The Tonga native was scheduled to fly to Utah tonight, Tollner said.

ESPN first reported Lotulelei has a left ventricle that is not operating at maximum capacity.

Lotulelei’s professional future could depend heavily on what doctors find. The Utah standout is considered one of the best prospects in this year’s draft. He is trying to join Alex Smith as the only players from the University of Utah to go No. 1 overall; San Francisco took Smith with the top pick in 2005.

Uncovering information like this is the reason the combine actually began in the late 1980s. Coaches and general managers have said for years that medical checks are a crucial component of the combine, perhaps the most important data they get all week so they can make informed decisions on draft weekend.

"The No. 1 reason that this started was for medical reasons, and you bring everybody here and have a chance to look at 300-plus guys, X-rays, MRIs, and get your hands on those guys," Lions coach Jim Schwartz said Thursday. "Each step along the way it added a little bit more, whether it was physical testing, or mental testing, or interview process. Nothing stands alone. You’re not going to draft a guy based on a 15-minute interview at the combine, or based on one attempt at a broad jump at the combine. It’s all just part of the big picture."

This is not the first time a big-name player has been diagnosed with an illness or injury at the combine.

In 2009, doctors found a small stress fracture in the left foot of receiver Michael Crabtree. Crabtree was still chosen No. 10 overall by San Francisco and had a breakout season in 2012.

It’s also not unusual for doctors to send players with medical questions from Lucas Oil Stadium, where the combine is held, to a nearby hospital for more extensive examination. The shuttles certainly have been full this week.

Among those hoping to prove they will be healthy enough to play this season are running back Marcus Lattimore, trying to return from last fall’s gruesome knee injury, and top-rated cornerback Dee Milliner, who said he will undergo surgery next month for a torn labrum in his right shoulder.

The NFL future of three players — defensive lineman Walter Stewart, linebacker Jarvis Jones and defensive back D.J. Hayden — will depend heavily on what doctors tell teams. Stewart and Jones were both diagnosed with congenital spinal conditions and were told to give up football. Both were later cleared to return to the sport. Hayden said he tore the main artery to his heart in a practice collision in November.

But teams already knew about those conditions before coming to the combine. Lotulelei’s situation came as a major surprise.

Finding a potential ailment in a player with aspirations of going No. 1 is certainly not the norm, though it is not unprecedented. In 2011, defensive end Da’Quan Bowers came to the combine projected to go No. 1, but during a medical recheck, doctors found signs of potential long-term arthritis and some weakness in his surgically repaired right knee. Bowers wound up sliding out of the first round and wasn’t selected until No. 51 overall by Tampa Bay.