Reports surfaced in the British press that Grant, the Israeli who has close links with Abramovich and who was in charge when Chelsea reached the 2008 Champions League final, could return to Stamford Bridge to help Benitez.
But a Chelsea spokesman told Britain's domestic Press Association news agency: "There is no truth in the reports."
Benitez has set some unwanted new firsts since replacing Roberto Di Matteo and being handed the mantle of turning around the Champions League winners' flagging fortunes.
The Italian is the first Chelsea boss not to win one of his first three games in charge under Abramovich, the first not to witness a goal in his first two and the first to lose to east London club West Ham.
After Saturday's shock 3-1 loss to the Hammers, Benitez conceded that the task of reviving Chelsea could turn out to be a bigger challenge than he had envisaged.
After little more than a week in charge, Benitez has overseen two scoreless draws and an unexpected reverse that has left the club's Premier League title ambitions severely dented.
That run has done nothing to get onside those supporters disgruntled by the dismissal of Di Matteo and opposed to the appointment of Benitez, and the reaction of the visiting fans at Upton Park confirmed the strength of feeling against him.
Benitez's focus now shifts towards Wednesday's Champions League meeting with Danish side Nordsjaelland, a game Chelsea must win if they are to have any remaining chance of progressing to the knock-out stages of a competition they won last season.
Asked if he considered the job more challenging than he expected when he accepted the offer to replace Di Matteo until the end of the season, he said: "Could be. It's a top side in the middle of the season, and things aren't the best.
"We'll try to improve things, but it will take some time."
He added: "My concern is improving the team. If we do that, and start winning games, we'll be able to turn things around. The main thing for me is to improve the team. I'm not thinking about anything else."