According to L'Équipe, Frankfurt sporting director Timmo Hardung has begun discussions with Forest over a possible loan move for the 24-year-old, who spent the second half of last season with the Bundesliga club.
Kalimuendo made a positive impression during his previous spell in Germany, scoring six goals and providing an assist in 19 appearances. His contribution convinced Frankfurt to consider keeping him permanently, although the club ultimately did not activate the purchase option included in the original agreement.
The Frenchman returned to Nottingham Forest ahead of the current campaign but has found opportunities difficult to come by. He has played only 110 minutes this season, leaving him frustrated by his lack of involvement.
A move back to Frankfurt could offer the forward the opportunity to rediscover the form he showed in the Bundesliga, while giving the German club a familiar attacking option.
The proposed arrangement is understood to be a loan, with Frankfurt hoping to reach an agreement that suits both clubs.
Kalimuendo remains under contract at the City Ground until 2030, having joined Forest from Rennes in the summer of 2025.
His previous spell in Germany demonstrated that he can make an impact in the Bundesliga, and Frankfurt's interest reflects their desire to bring in a forward who already understands the club and its environment.
The club are not, however, only looking at experienced options. Frankfurt are also among the sides interested in Paris Saint-Germain youngster David Boly, the 17-year-old right-back who has attracted attention after scoring against Villarreal in the Champions League.
According to L'Équipe, Frankfurt would be prepared to pay a transfer fee to PSG in January to get ahead of the competition.
Boly is currently understood to favour remaining with his formative club, however, meaning Frankfurt face a difficult task if they want to secure his signature.
For now, Kalimuendo appears the more immediate target as the German side look to strengthen their attack during the winter window.