Guiton spent the last three seasons as a backup to Braxton Miller, considered among the favorites for the Heisman Trophy this season, and earned fame when he replaced an injured Miller for a comeback win over Purdue in 2012.
He started twice for the Buckeyes last season, the only two starts of his college career, completing 69 percent of his passes, with 14 touchdowns and two interceptions. Guiton was also a threat as a runner, gaining 330 yards on 40 attempts, with five rushing touchdowns.
If the Bills eventually offer Guiton a contract, he'd be the fifth quarterback on the Bills' roster.
The Bills are also hosting a trio of wide receivers on tryouts during their rookie minicamp, which begins Saturday. Caleb Holley from East Central University, a Division II school in Oklahoma, is the tallest of the bunch, at 6-foot-4. UB's Fred Lee is 6-foot-2, while West Virginia's Ivan McCartney is 6-foot-2.
On Friday, the Bills waived wide receiver Brandon Kaufman, opening one spot on their 90-man roster. Kaufman, who is 6-foot-5, said earlier this offseason that he could move to tight end, but he was buried on the depth chart in either case.
It's not a coincidence that the Bills are hosting three taller receivers this weekend. The Bills continue to search for height at the position, already having added Ramses Barden (6-foot-6) and Chris Summers (6-foot-5) this offseason.