"Michael is back in the squad and I'm looking at giving him an hour," Redknapp told the club's official website.
"That's as much as we can expect of him as he's been out for a long time.
"He's a fantastic lad and a good player for us and it's great to have him back but we don't want to see him break down again in what will be his first game back."
Redknapp has also confirmed that Heurelho Gomes will replace Carlo Cudicini in goal.
"Gomes will play at Preston," he said.
"They are both good goalkeepers, so it's a good position to be in."