The 21-year-old, on the road to recovery following two cruciate knee ligament injuries, is poised to sign a one-year contract at Oakwell.
Coulson said: "The club didn't have to offer me a new deal, but Simon (Davey) has been brilliant with me. I'm ready to sign.
"It's been so frustrating for me sat on the sidelines and not being able to play. But Simon said I'd get a new deal and I really want to show him and the supporters what I'm capable of."
The former Scarborough man added: "To do it (suffer a cruciate
injury) twice in one season in unbelievable really. I don't know many footballers who have ever done that.
"It's been so hard, but the club have kept faith in me and that means a lot. I want to repay them with some goals."