The Reds were heavily linked with a move to sign the Guinea international throughout the summer window and eventually got their man when they agreed a deal to land the midfielder for next summer.
Chelsea, meanwhile, opted to strengthen their team with the likes of Tiemoue Bakayoko and Danny Drinkwater in midfield as Antonio Conte prepared for his second season in charge at the club.
However, former Liverpool man Collymore believes that the Blues are still lacking in midfield and feels that the west London side could struggle in the Champions League this season.
Collymore told the Daily Mirror: “Even though Chelsea have won their last three games in the Premier League and things seem to have settled behind the scenes, I don’t think they have added to their squad enough for Conte’s liking when it comes to the Champions League.
“I expected them to be in for a Naby Keita, a Leonardo Bonucci — players who were up for grabs in the summer — and they didn’t get them, even though I suspect their manager wanted them.”
Midfielder Keita will link up with Liverpool next summer after he plays one final season at German side RB Leipzig.
Chelsea take on Arsenal in their next Premier League game at Stamford Bridge on Sunday afternoon as they look to make it four wins on the trot in the top flight.
Arsenal head into the game fresh from their 3-0 victory over Bournemouth at The Emirates last weekend, while Chelsea were 2-1 winners at Leicester City.
Liverpool, meanwhile, host Burnley at Anfield on Saturday afternoon.
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