Michael looked a certain matchwinner in the 72nd minute when Sylvain Distin's mistimed attempt at clearing Geremi's corner landed the ball on his foot. But his volley from eight yards flashed over the bar, after hitting James on the head.
Redknapp saw his FA Cup finalists keep a clean sheet for the 22nd time this season and said: "That was a save by Jamo. The shot hit his head and went over.
"He's had two great seasons for us and I couldn't tell you how many points he's been worth to us in that time. He hasn't had too many scary moments for us although there were one or two today.
"But it's great for him to be nominated in the player of the year shortlist even though I'm still convinced (Cristiano) Ronaldo will win it.
"I knew it would be tough today. Newcastle have been on a good run and it was all pretty tight out there. Without John Utaka we don't have too much width and the pitch was also a bit bumpy.
"The lads have been great and did well in midweek to win at West Ham but I think they were a bit tired today."
Redknapp claimed Pompey could "easily have had a penalty" when Kanu's shot struck defender Steve Taylor's arm after rebounding off his heel just before the break.
Redknapp added: "The ball came off his foot and I don't think he meant to play it with his arm - but I've seen them given."