The former striker told talkSport radio on Thursday that talk of replacing Redknapp at Loftus Road was "a little bit premature."
"We've seen this movie before guys, haven't we Mark Hughes, Neil Warnock, same time of year, bad results, the same thing happened. Sack the manager, sack Hughes, sack Warnock, bring in Harry, he doesn't save QPR but gets them promoted.
"We are seven or eight games in and it is sack the manager again. It's the same thing around and around and around," said Marsh.
Rangers are bottom of the Premier League with four points from seven games since they won promotion in the Championship playoffs last season.
The West London side have only one win to their credit and the worst goal difference in the Premier League, with only four goals scored to 15 conceded.
Redknapp, who was talking about a contract extension only recently, is increasingly under pressure with the media speculating on who might replace him while players have spoken out in support.
"We are not even in double figures for the amount of games played yet," former England captain Rio Ferdinand, himself under pressure after laboured performances, told the Evening Standard. "To push the panic button now would be crazy in my eyes.
"He wants to get the club out of this situation we're in. It's not for the lack of trying."
The names of former Tottenham Hotspur head coach Tim Sherwood has been mentioned as well as former Stoke City and Crystal Palace manager Tony Pulis -- two very different characters.
The appointment this month of former QPR striker Les Ferdinand as head of football operations raised eyebrows but Marsh said the arrival of former England manager Glenn Hoddle in August as first-team coach had really surprised him.
"Did Harry know about Glenn Hoddle coming on and then did he know about Les Ferdinand coming on," he asked.
"Those two have really shocked me. Hiring Glenn Hoddle for Queens Park Rangers is like asking Picasso to teach painting by numbers. I just don't get that one."
Marsh said QPR had failed again to bring in players with the spirit and fight to keep them in the Premier League and only Joey Barton had shown the required strength of character.
"We had this situation the year before last, the five or six players they brought in were all journeymen on big salaries and it seems to me as though the same thing has happened again," said the former striker.
He singled out Ferdinand, now 35, for particular criticism.
"If he was up for it and motivated, he'd be a fantastic player," Marsh of the former Manchester United stalwart.
"He has turned out to be a total ricket signing, Rio Ferdinand, and how Harry keeps him in the team is beyond me."
QPR host Liverpool in the Premier League on Sunday.