As the AFC's top seed, the Broncos have this weekend off before opening the playoffs the following week. They've allotted time for teams interested in McCoy to interview him in Denver this weekend.
Horton has already interviewed twice with the Cardinals, and once with the Browns, before revealing to reporters at the Cardinals' facility that he was set to meet with the Bills.
"I'm excited about the opportunity here, and the fantastic interview I had with Cleveland last night, and am going to try to knock Buffalo's socks off," Horton said.
Horton and Whisenhunt not only coached with the Cardinals, but they also previously coached in Pittsburgh.
That makes them both quite familiar with Bills assistant general manager Doug Whaley, who is a member of the team's search committee. Whaley, who is being groomed as GM Buddy Nix's successor, spent nine seasons working as a Steelers scout before joining the Bills three years ago. He is a Pittsburgh native, as well, and played his college ball at Pitt.
Whaley, on Tuesday, spoke highly of both Whisenhunt and Horton.
"We go way back. We've won some Super Bowls together, so I have high regard for their coaching acumen," he said. "I don't think it will make a decision on if they're going to be our coach, but I can shed some insight on how they performed when I was with them and as persons."
AP College Football Writer John Marshall in Scottsdale, Ariz., and AP Sports Writer Tom Withers in Cleveland contributed to this report.
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