Whelan said: “If you go back in history, you will find most successful clubs have had two centre-forwards with a great understanding who would score goals and feed off each other week in and week out.
“At Liverpool, you just have to think of Ian Rush and Kenny Dalglish, and Kevin Keegan and John Toshack.
“Now it’s Bellamy and Crouch in one game, Kuyt and Crouch in the next, then Kuyt and Luis Garcia or any number of other permutations.
“You cannot get an understanding going. It’s the same for two central defenders or two full-backs who play together regularly. They know where they will be at any given time.
“But with the rotation system I don’t think you can get that same understanding.”