The Pools boss has revealed that the Championship club have recalled the midfielder, who has made 25 appearances for Pools this season.
“We thought we had a deal in place but Middlesbrough have changed tack a little bit and they want their new manager to have a look at all of their players," Cooper said.
“It is disappointing but we’ll get on with things. We have competition for places and this gives someone else an opportunity.”
IOR fully understand Middlesbrough's request and hope that, in the next two weeks, the position will be clarified following their assessment of Dolan.