Hakeem Butler refining game under tutelage of Calvin Johnson, Anquan Boldin

Indianapolis — About the only thing bigger than Iowa State wide receiver Hakeem Butler at the NFL's scouting combine is the assist he's been getting with his preparation for the draft. 

Checking in slightly bigger than 6-foot-5, Butler is the tallest receiver at the event. And, in his opinion, he's also the best. But he's not about to resting on the laurels of his 60-catch,1,318-yard season in 2018. He's also not waiting until he's drafted to develop his game. In the months leading up to finding out where he'll begin his professional career, Butler has been working to refine his game with former NFL superstars Calvin Johnson and Anquan Boldin.

Butler trains out of the same facility as Boldin in Florida and got connected with Johnson, the longtime Detroit Lions standout and future Hall of Famer, through agent Bus Cook. 

The NFL released a short video of the two going through on-field workouts last week, with Johnson emphasizing how techniques on how to beat man coverage. 

Butler admitted he's been a little awestruck through the interaction. 

"It was a surreal experience," Butler said. "Calvin Johnson, I had to keep my cool, at first. You want to fan girl a little bit. (That's) someone I watched growing up. I kept my cool and I don't think he knows, but every word he gives me I'm hanging on. It means a great deal to me and I hang on every word."

Butler said he's one of the key things he's taken away from both Boldin and Johnson is their relentless mentality to be great. Johnson also emphasized the importance of never losing the chip on your shoulder.

On the field, Butler explained the advice Johnson has offered. 

"That the man across from you is trying to take your head off, so you have to take their head off first," Butler said. 

Butler is unique, not simply because of his size, but because of how he was utilized at Iowa State. Most big receivers are pinned out wide, where they can take advantage of their size in space, but a significant portion of Butler's production came in the slot. 

He credited his basketball background for his success operating tighter to the formation. 

"A lot of coaches think 6-6, you're a little stiff, but I've got a little wiggle to me," he said. "I've got a little short guy to me in there somewhere and he comes out every now and then."

Butler was also highly productive after the catch, a mentality he developed and maintained as a young player with the Cyclones. 

"When the ball is in my hand, I've got to score every time," Butler said. "I think my redshirt freshman year I maybe had eight catches. Every time I caught it, I tried to score because you never know when that ball is coming back to you. 

"Even when I became the man at Iowa State, or the go-to receiver, I still never knew when it was coming back to me. That's how I treated it. I tried to score every time I touched it."

For his college career Butler scored on 16.4 percent of his catches. He's expected to be selected in the first two rounds of the draft.  

As for Johnson, Butler is convinced the former Lions receiver could return to football and dominate, if he wanted to. 

"He could come play right now, first overall pick in this year's draft. Maybe second after me," Butler said with a laugh.