The France international joined the Blues in the summer from champions Leicester.
And the midfield maestro hasn’t looked back since his switch.
“He doesn’t score many goals or provide many assists — he scored just one in 2016 and only created another two — but there hasn’t been a more influential player in the league,” Carragher wrote the Daily Mail.
“I highlighted him 12 months ago for being that season’s outstanding signing, following his £5.6m move from Caen to Leicester.
“The drop Leicester suffered and the upturn Chelsea have enjoyed hasn’t all been because of this marathon man — but his importance cannot be overstated.”