PROVO, Utah (AP) Kalani Sitake is the popular new coach at BYU, but Ty Detmer and Tanner Mangum were swarmed by the two biggest crowds following the spring game Saturday.

Detmer, the Heisman-winning quarterback turned offensive coordinator, and Mangum, the Cougars' current hot-shot signal-caller, will be linked the next three years as the success of one will likely determine the success of the other.

Mangum, unofficially, remains atop the depth chart as senior Taysom Hill continues to work his way back from a season-ending Lisfranc injury. He was limited throughout the spring session and didn't participate Saturday due to the sudden death of this brother Dexter Hill on Friday.

More from FoxSports

Mangum is looking to build off a fantastic freshman year in which he set BYU freshman records for passing yards (3,377) and touchdown passes (23). The passing yards were the most by a BYU quarterback since 2009 and Mangum became a national sensation with final-drive comeback wins against Nebraska and Boise State. Now he has a new system to learn under a first-year offensive coordinator that happened to play 14 years in the NFL.

''He's awesome,'' Mangum said. ''Basically everyone already knows. They can tell he's a very smart coach. Knows what he's doing. Knows what he's talking about. Very competitive. But at the same time, very relatable. Easy to talk to, easy to work with. I've been having a blast.

''I wish there was more time because I've still got a lot to learn from him. It's been good to be able to soak up his knowledge and be able to learn from his experience.''

BYU has dumped the no-huddle spread offense run under the former regime for a more pro-style attack with the team huddling up and the quarterback under center. Detmer said much of the spring was spent learning more about the players and what they can and cannot do. He's thankful that Mangum and Hill have some experience under their belts, which allows them to understand concepts quicker and implement certain checks at the line of scrimmage.

''You want to see Tanner out there throwing it and see what he can do and how he picks up the new concepts and some of the formations,'' Detmer said. ''Just knowing where everyone's going to be. He's a guy that I haven't coached before. So you want to see them out there, how they handle themselves when good things happen, when bad things happen and how they lead the team.''

This is the first spring session for Mangum, who was still on his Mormon mission at this time last year. He returned in the summer and was starting Game 2 after Hill was injured early in the season-opener. Mangum's goal for spring was to be in command regardless of the situation. To be decisive and make good decisions within the new offense. Detmer hasn't opened up the entire playbook for the team yet and Mangum admitted he doesn't have it all down yet. He's put on some weight and is up to 215 pounds - he was listed at 195 in the 2015 media guide - and also feels quicker.

Sitake said Mangum's biggest strides have come in the leadership area, something that has improved even since February.

''He's kind of always had that,'' senior receiver Nick Kurtz said. ''Whenever you have a good quarterback you really pretty much just listen to whatever they say. That's just kind of how it works. He's the play-caller. He's the shot-caller. So we trust in him with everything that he does.

''He's amazing. He's an accurate quarterback. You trust in the guy. He's a natural leader. And somehow he works miracles, too. So we like that.''

Sitake kept the Spring Game fairly bland with a 7 on 7 period before some full action. Mangum played sparingly and threw for 82 yards and a touchdown.

The fall will be interesting as Mangum tries to hold onto the starting job against Hill, who was a Heisman candidate in 2013, but has had injuries derail his career. Either way, 2016 will be the last year Hill is in the mix.

The Mangum-Detmer relationship has three years to blossom. The first criticism of the Detmer hire is that he has only coached high school, but a successful Mangum will make that transition much easier.

In the meanwhile, Detmer remains a BYU celebrity with a quarterback that has already put himself in the school's record books.

''Probably when the games start and people start booing your play calls,'' said Detmer, when asked when fans will see him as coach. ''Then you become the coach. It'll always be a little bit of both here. I don't mind it.''