A Reuters report last week suggested Fertitta was looking for a "reverse merger," where Caesars would be the majority party in a joint venture with his own gaming empire.
But the New York Post has reported the Caesars board is set to unanimously reject the deal this week.
The publication quoted a source suggesting the offer is "certainly not attractive."
Sources said Caesars still has a $9bn debt following its emergence from bankruptcy a year ago, with Fertitta’s net worth valued at $4.5bn.
Meanwhile, Caesars remains keen on purchasing Jack Entertainment in a deal worth over $1bn, aiming to avoid any Fertitta speculation delaying that process.
Caesars told Gambling Insider it would make no comment when contacted about the merger offer last week.