Redknapp has admitted he is keen to sign three new players before the start of the Premier League season and although Young is reported to be a target, the Spurs boss will not be making enquiries about the winger or Milner, who is the subject of interest from Manchester City.
When asked if Spurs are considering a move for Milner, Redknapp told Sky Sports News: "No, we wouldn't be able to. Anybody would like James Milner, he's an outstanding young player, but he'd be way out of our depth."
On Young, Redknapp said: "Again, I wouldn't think they'd want to sell Ashley Young. He is a good player but he belongs to Villa. We've not made any enquiries for him at all."
Everton defender Jagielka is also reported to be a Tottenham target and although Redknapp is in the market for a defender, he will not be troubling David Moyes with a phone call.
Redknapp said regarding Jagielka: "A good player again, outstanding player, but we wouldn't be in the market for someone like that."
However, Redknapp has reiterated his interest in Spartak Moscow and Croatia goalkeeper Stipe Pletikosa.
"I think Daniel [Levy, chairman] is talking to him and there is a possibility of loaning him," Redknapp said. "We have two outstanding goalkeepers in (Heurelho) Gomes and Carlo Cudicini but I do feel that maybe we need three keepers with European games coming up."