Redknapp, who will be 66 on Saturday, was in charge of Southampton when they were relegated from the Premier League in 2005 and then, to add insult to injury, left a few months later to take over at bitter rivals Portsmouth.
"It is my first trip back to Southampton. I will get a bit of grief I am sure. Southampton supporters are good supporters," Redknapp told a news conference on Friday.
"I won't lose sleep over it. I will only do that if we get beat.
"No one was more upset than I was that Southampton got relegated. I gave everything I had."
QPR, who have won only twice this season, are bottom of the table with 17 points, seven from the safety zone. Southampton, whose manager Mauricio Pochettino also has a birthday on Saturday, are two places above the relegation zone on 27 points.
"It is getting more difficult (to turn it round). We need back-to-back wins. That is something we need to do," said Redknapp whose side's last victory was 1-0 over Chelsea on Jan. 2.
"I have got to be upbeat. If I start saying we will get relegated we might as well go on our summer holidays."
QPR will be without striker Bobby Zamora for Saturday's trip.
"Bobby is struggling. He won't be available as he has done his ankle; there's no way he can play," Redknapp said.
Zamora, QPR's top scorer this season with five goals in total, injured his ankle last weekend.