Hooper has been impressive form for Celtic, whom he joined from the Iron in the summer, with 15 goals to his name this season.
He had been linked with a call-up to the senior England team, but has instead been included in Stuart Pearce's U21 squad to face Denmark in Viborg on March 24 then host Iceland four days later.
Pearce, the U21 coach, has named a large 31-man squad to allow the players to stake a claim for a place in his European Championship finals squad for this summer.
“There are one or two fresh faces in there such as Hooper and Mark Davies (of Bolton Wanderers) but in the main the majority of the players are well known to us and have been involved in the qualifying for the tournament," he said.
“Now’s the time for all of the players to impress in the minds of the coaching staff that they want to be the ones stepping on to the plane. At the end of this meet-up I need to be able to make some final decisions about my squad – and I will.
“Both of the teams we’ll face will be in the Championship in June so there can be no better warm-up opportunity for us and there will be no underestimating anyone on our part, and I expect the opposition will be thinking much the same about us.”