Friedel arrived on a Bosman in the summer from Aston Villa.
Redknapp told the Spurs website: "Brad, again, he's a fantastic professional, his record of consecutive games in the Barclays Premier League has been amazing.
"He was a big signing for us, but it was difficult because I've got two other great goalkeepers here. Gomes is a fantastic goalkeeper and Carlo Cudicini as well.
"So it was a difficult one, but I just thought, I need three goalkeepers and Brad was available and he's come in to the team and he's been magnificent.
"Even in the couple of defeats that we had early on, I thought his performances were top class. He's a top professional and a fantastic guy."