Keeper Cody Cropper needs to improve if he is to push David Martin for the number 1 jersey at MK Dons.
Cropper, an American U23 international, joins the club from Southampton having trained with Dons in the latter part of last season.
He joins David Martin and Charlie Burns in the goalkeeping ranks, but Robinson believes he must improve if he wants to become a regular in the first team.
“He wants to push Dave,” said the manager. “He’s a third choice international keeper so he doesn’t just want to sit around here.
“He’s a tremendous specimen and a great size.
“He came in at the back end of last season and we were relatively impressed.
“He has a great work ethic, which a lot of Americans have.
“There are elements of his game we can improve. But when he became available, it was a no brainer.”
Cropper added: “It’s a great opportunity for myself and I’m very pleased to be here.
“I want to push on and develop as a goalkeeper.”