Brinson, a rangy 2014 cornerback, committed to Iowa State in September but took a visit to Indiana in October without telling the ISU coaching staff, which wasn't pleased when it later learned of the trip to Bloomington. Brinson has told AllCyclones.com he's still committed to Iowa State but isn't sure if the offer still stands.
On Monday, Shafer said he needs to see a resolution.
"If Iowa State drags their feet then we're gonna have to decommit," Shafer told AllCyclones.com. "(Defensive coordinator) Wally (Burnham) was supposed to call me, I want to make sure the scholarship is [good].
"[Dedric] desires to be at Iowa State. We come back to school tomorrow. I'll figure it out then. But I have to know because other schools are interested and he's too good an athlete to find out at the last minute the head coach is pulling his scholarship."
Shafer said Burnham told him before Christmas that everything was "OK," but a decision will ultimately be head coach Palu Rhoads' to make.
Iowa State has had committed prospects take visits elsewhere this season but asks such players to be forthcoming about that information.
"Dedric should have told Wally about it ahead of time," Shafer said. "He went on that Indiana visit because of teammate Davi'on Riley, a really good tight end. Indiana called Riley and convinced him to take Brinson. They're good friends."
Since then, there's been little doubt where Brinson wants to play his college football.
"I know for him, when he's walking around the halls here at school, Iowa State colors are all he wears," Shafer said. "Indiana still wants him, but he wants to go to Iowa State. That's his first choice."