The Cameroon international joined Portsmouth from Arsenal, in a deal worth £500,000.
Redknapp said: “I thought Lauren did well. We pushed him inside later on and he did well there, too. He’s a good player, a proper player. He’s over his knee problems now. He came through the game on a muddy pitch with no problems.
“He had a better offer from West Ham but decided to come to us. Glen Johnson’s on loan and I imagine he will go back to Chelsea.
“So if you get an opportunity to go for a player like Lauren, you’ve got to go for it. He came for £500,000 not £1.5m as was said at first. He will be important for us over the next couple of years.”