"Nebraska is not completely out," Hetzer told InsideTheVille.com. "I'm waiting to hear from the coaches on their evaluation from the athletic director. If I find that the coaches won't be there they will definitely be out for me."
If Callahan is out at Nebraska, Louisville would likely be in for Hetzer, who expects to graduate from Citrus (CA) College in December.
"I'm just waiting to see what the coaches are like at Louisville," said Hetzer, who will make his official visit to Louisville Dec. 6-8. "I want to limit who I consider. I am definitely interested in Louisville. They are definitely No. 2, if not No. 1, on my list. I've always wanted to play in the PAC 10 so if Arizona were to call me I'd definitely consider them but right now I'm mainly considering Louisville and Ole Miss. I'm really committed to Louisville and interested in them."
If Hetzer's visit to Louisville goes well, he says there's a solid chance he could leave town committed to the Cardinals.
"I'm going to have to make a decision soon," he said. "There is a good chance I could commit on my visit to Louisville. But I don't really know right now."
Hetzer is also looking into possibly visiting Ole Miss, too.
"I'm just waiting to go on that (Louisville) visit and I think I'm going to visit Ole Miss pretty soon as well," Hetzer said. "So that's it basically right now for me. I don't know when I'll visit Ole Miss because I'm still waiting to hear from their coach but I'm expecting it to be sometime in December or later this month."
Louisville, needing a tight end to step in next year and replace Gary Barnidge and Scott Kuhn, made contact with Hetzer about three weeks ago. Louisville assistant Mark Nelson travelled to California and was impressed with what he found in Hetzer, who the Cards have offered.
"Basically they just like that I have the ability to stretch the field and have good hands," Hetzer said. "One of the big perks is that I've never really been coached how to block as a tight end. I've just kind of gone out there and done it myself. And so they're going to help me with all of that.
"The coach that I met that came out here was a really good guy and just watching a lot of their games this I saw that they throw to their tight ends a lot," Hetzer said. "I'm waiting to go on my visit to see how much more I like them."
Hester caught 13 passes for 152 yards and one touchdown in just six games this season.
"We went 6-4 including our bowl game, but overall it was a fairly decent season," Hetzer said. "Personally, I did pretty good. I didn't get a lot of balls thrown to me because that's not my coaches style of offense but the passes that did get thrown to me I pretty much caught all of them. I only had two drops this whole year. I blocked about 80-90 percent, somewhere in there, this season."