But Redknapp hopes the Gunners talisman does not spark an end-of-season surge at Emirates Stadium.
The 34-year-old rejoined the club he left for Barcelona in 2007 on a short-term loan deal from the New York Red Bulls - and enjoyed a dream second debut when he came off the bench to score as Arsenal beat Leeds 1-0 to book a place in the fourth round of the FA Cup.
Henry will be available for a six-week spell which will take in matches against Manchester United and, in the Champions League, AC Milan - as well as possibly even the showdown with arch-rivals Spurs at Emirates Stadium on February 26.
Third-placed Tottenham could put further distance between themselves and Arsenal with victory over Everton on Wednesday night.
Redknapp, though, is wary of the lift Henry's return could give their north London neighbours.
"I watched the game and knew Henry would score, it was written, some are meant to happen. It was just amazing," the Spurs boss said.
"I hope he doesn't make too big an impact because we want to finish above Arsenal this season, which is not going to be easy, but I am sure he will have some impact on the football club.
"Having people like that around the place is worth their weight in gold. They make a difference when they walk into the club.
"They are good professionals with good habits, the young players can learn more from watching them every day than they can from being coached by anybody."
Gunners boss Arsene Wenger last night revealed the club could push for a two-week extension to Henry's loan deal ahead of the new Major League Soccer season, which would see him available to face Spurs.
Redknapp joked he already had a plan in place to cope with Henry.
"We might combat him with either [Glenn] Hoddle or [Ossie] Ardiles, so we will be ready for him. Graham Roberts or Paul Miller are going to come out of retirement to kick him," Redknapp quipped.
Henry's return to action followed the shock decision by veteran midfielder Paul Scholes to come out of retirement and play for Manchester United in their FA Cup win at Manchester City.
Tottenham were unable to sort a deal to bring in former England captain David Beckham from Los Angeles Galaxy last season, after he had a spell training at their Essex base.
Redknapp believes the next generation can learn a lot from such model professionals.
"Manchester United have turned to Paul Scholes, Arsenal have turned to Thierry Henry. It's a bit scary when you look around and see they are still better than some of the younger players," the Tottenham manager said.
"Scholes comes out of retirement at 37, him and Ryan Giggs play in the midfield together at Manchester City, and can still be better than anybody else at Manchester United. It is amazing.
"There are still a lot of old ones about who can make the difference and people have to understand experience is something you cannot give to people."
