Everton had been considering a bid of up £18 million ($23m) for Batshuayi given they are unable to sign him on loan.
Chelsea defender Kurt Zouma is already plying his trade at Goodison Park on a temporary basis, with Premier League rules stating a maximum of one player can be loaned to another club at any one time.
Were they to sell, Chelsea would likely want to recoup the £33m ($42m) they spent to sign Batshuayi from Marseille in 2016, and as such another loan deal looks most likely this January.
Should he complete the move to the Ligue 1 strugglers then he would reunite with Thierry Henry, with the former Arsenal striker and current Monaco manager having previously worked as a coach for the Belgian national team.
"I know him well, we were close with Belgium," Henry said of the forward. "We'll see what happens. He's an interesting player."
Batshuayi would also become the second Chelsea player to move to the Stade Louis II during the January window, with Cesc Fabregas set to complete his permanent transfer once a replacement is found by Maurizio Sarri's side.
A move back to the French league could be exactly what Batshuayi needs having struggled for form during his time with Valencia during the first half of the season.
He scored just three goals in 23 appearances for Los Che, with manager Marcelino suggesting that patience had run out with the ex-Borussia Dortmund loanee after he was substituted at half-time of Tuesday's Copa del Rey defeat to Sporting Gijon of the Segunda Division.
Meanwhile, Chelsea's pursuit of Napoli full-back Elseid Hysaj has been put on hold until the summer transfer window opens.
The Albania international was a key player for Sarri during his time with the Serie A high-flyers, and it had been hoped he could be tempted to move to the Premier League this January.
But the player recently held talks with the Napoli hierarchy and committed himself to the club until the end of the season as they look to mount an unlikely challenge to catch current leaders Juventus.