It is believed that the Latics are holding out for a straight £9 million up front with Chelsea only prepared to offer £6 million up front and the remaining £3 million due in add ons.
With Crystal Palace believed to have a 10% sell on clause resulting from Moses' move to the Latics nearly three years ago, Whelan is keen to maximise his sale prices.
Speaking about the speculation, Whelan said: "Chelsea have got to make their mind up - yes or no - and at present they're messing about a little bit which is unusual for Chelsea because they're up front if they want someone. They would usually go and make a bid and get the player.
"With Victor, Chelsea have come in with offers including payments later etc. It's unusual for Chelsea because they're usually a very straightforward club.
"If they come with the fee, we'll sell him. If they don't, we'll keep him."
At present it is expected that Moses will line up in a Wigan Athletic shirt this weekend against opponents and potential suitors Chelsea in the new season kick off.