The Sky Sports pundit was speaking after Arsene Wenger's side suffered a 6-0 defeat away at Chelsea on Saturday, a result that sees them fall seven points behind the league leaders with eight games to play, albeit with a game in hand.
Chelsea were 3-0 ahead as early as the 15th minute, but Redknapp felt the story of the game could have been different if Olivier Giroud had finished an early gilt-edged chance before Samuel Eto'o opened the scoring.
He now feels Arsenal won't go on to challenge for this year's Premier League title - and urged Wenger to sign a clinical goalscorer in the summer if they are to give themselves a better chance next term.
"Arsenal have had too many beatings in the big games; that's the problem," said Redknapp of a side that has lost 6-3 to Manchester City and 5-1 to Liverpool this season.
"There was a big moment in that game when Giroud went through three minutes into the game and should have scored but he didn't and Eto'o went and scored up the other end.
"That is symptomatic of Arsenal's problems. They haven't been able to produce in big matches. That's when their defensive frailties come to the forefront.
"I'm not trying to pick on Giroud but the best sides [convert] the best moments. When you look at Manchester United last year, there were moments when they were struggling but Robin van Persie scored that all-important goal to take the pressure off the whole team.
"Giroud just isn't capable of doing that and I think that's something that Arsene Wenger has to address in the summer.
"I think you can pretty much rule Arsenal out [of the title race] now - they've got too much to do. That performance would have absolutely killed them today."