Redknapp has made no secret of his desire to bring new faces to the west Londoners, who are bottom of the Premier League and four points adrift of safety.
Full-back Yun Suk-young joined Loic Remy and Tal Ben Haim as QPR's acquisitions so far this month, but Redknapp revealed he is still "desperately short" after Tuesday night's 0-0 draw with Manchester City.
"I'm sure there will be a few arrivals and some going out," Derry said. "We have got no say in that as players, we can only do what is asked
"I am always glued to the TV on deadline day. I'm like a fan.
"It is exciting to watch it and I will be interested who we bring in.
"Obviously Harry is wanting to enhance the squad. That's what he's about on deadline day - he comes to life, doesn't he? I'm sure he will be excited come Thursday.
"But as far as being in trouble if we don't add to the squad, we've proved against Manchester City that we can get a result against the league champions with the players we've already got. We can take great heart from that."
A key priority for Redknapp will be strengthening at centre-back, with Anzhi defender Christopher Samba poised to complete a move after the Hoops triggered his release clause.
The former Blackburn defender could now be on his way back to the Premier League as QPR look to fill the void left by Anton Ferdinand's loan move to Bursaspor and Ryan Nelsen's impending departure.
The New Zealander is set to leave the Rs on February 1 to become head coach of Toronto FC and was given a guard of honour after helping the Hoops to a clean sheet against City.
"It is a big loss for us," Derry said. "He has been our best player this year but we have to try and replace him.
"He has been amazing, not just as a player, but as a person as well.
"It was Clint Hill's idea to give him a guard of honour at the end.
"We were all just buzzing to get the point and it was a great gesture by Clint. It was appreciated by Ryan, but he's appreciated by all of us.
"He said afterwards that he couldn't believe the send-off he got from the crowd too because he's barely played 25 games for us. It was touching for Ryan."
QPR's performance against the reigning champions was a vast improvement on the embarrassing 4-2 FA Cup defeat to MK Dons, after which reports claimed there was a dressing room bust-up.
"Listen, things get said after games in changing rooms up and down the country, the length and breadth," Derry said.
"Things get said in the heat of the moment.
"We were disappointed going out of the cup, we really were, and the way we went out was even more disappointing than the result itself.
"I think we proved a point against City. That performance showed everybody we are together.
"I'm from the old school and I like to discuss both positives and negatives.
"Obviously when you come off the field losing 4-2 in the manner that we did, we had to reply in the right manner against Manchester City and we definitely showed that."