After watching his side gain a fortunate 1-1 draw against West Brom in front of just 8,984 fans at Loftus Road in the FA Cup third round, the boss of the Barclays Premier League's bottom club revealed he faces losing key defender and club vice-captain Ryan Nelsen in the January transfer window.
Nelsen, 35, has been linked with a move to the MLS in America, potentially with former club DC United, and Redknapp believes if he goes it would be a major blow to QPR's survival hopes in the Premier League.
Redknapp said: "Nelsen is very important to us, a fantastic leader, a top player. But he has been offered a job in America and I think there is every chance he might want to go.
"He wants to be a manager and it is a chance for him to manage a club.
"He has been fantastic. I took him to Tottenham last year from Blackburn. He's one of the best pros I've ever met in my life, a fantastic player, a great trainer. He is a massive part of your team. To lose him would be a massive blow for us."
Nelsen has six months remaining of a one-year deal but Redknapp said: "I'll have to speak to the owner to see what the situation is with that. We'll try (to keep him) but it is difficult."
Nelsen was substituted against West Brom in the second half with a sore knee but even Kieron Dyer's injury-time equaliser, his first goal since May 2007, to secure a replay at The Hawthorns could not take Redknapp's mind off his league worries.
Redknapp, whose side lacked the solidity and verve they showed in beating Chelsea at Stamford Bridge in midweek, said: "Whoever we would be playing I would be thinking about next week's league game.
"We've got to pick up league points. I'll be flying all round the world to try to get one or two players if I can. That's the key. We need to improve the squad. I'll be doing everything I can to do that.
"We have to do business somewhere even if it's loans. We are short in certain areas. The team needs picking up."
Whether Dyer makes Redknapp's 25-man squad at the end of the transfer window is by no means certain.
The 34-year-old has spent the last five years under an injury cloud and Saturday was only his third appearance of the season, although he took his goal with the aplomb of a striker who won 33 caps for England.
Redknapp said: "He's been injured for years. It was just nice for him to get a full game in."
One man Redknapp was delighted to welcome back was striker DJ Campbell who scored 10 goals in an impressive 17-match loan spell at Ipswich and was QPR's liveliest player.
"I've had seven or eight clubs in for DJ Campbell from the Championship," said Redknapp.
"He gives everything. I like him a lot as a lad. He has got a good attitude. He will be handy for us. I wish I had had him here a month ago."
Redknapp also revealed Bobby Zamora is "not too far away" from returning after surgery for a hip injury.
West Brom, who had already beaten QPR twice this season in the league and had to contend with a potentially serious knee injury to Zoltan Gera in the first half, took the lead through Shane Long and were by far the more penetrative.
Assistant coach Kevin Keen insisted they were confident of finishing the job in the replay.
He said: "We'll have a real go at The Hawthorns. Our record is good there. We're confident playing at home against anybody.
"What happened in the last 30 seconds can happen in any game and an old friend of mine, Kieron Dyer, has popped up with a goal. I can't remember the last time he scored. These things happen in football, that's why we all come to watch.
"We're a fraction disappointed but we've done well. Their goalkeeper made two or three good saves."