Redknapp is currently in Portugal watching Euro 2004 and scouting on possible new signings.
The Pompey chief has admitted that central defensive pair Dellas and Muller have caught his attention with their displays.
Dellas has been inspirational for surprise package for Greece, while Muller helped Switzerland keep a clean sheet against Croatia in their opening game.
"I want to go out at the weekend and watch Greece again, when they play Russia," Redknapp told The Times.
"I thought they had some good players in midfield and I was so impressed with Traianos Dellas, the central defender.
"He looked solid and very comfortable on the ball, and there could be a chance of getting him on loan - Roma tried to loan him out a couple of times last season.
"It's in his favour that he knows the English game, from when he had a spell at Sheffield United, and he's gone on from there and done well.
"There's another defender Patrick Muller who plays for Switzerland, that impressed me and he's someone who could be worth a look without spending a fortune."
