The 25-year-old joined Frankfurt from fellow Bundesliga club Wolfsburg in 2023 and has since established himself as a star player for Dino Toppmoller's side.
Marmoush contributed with 17 goals and six assists in 41 appearances for the Eagles across all competitions last season and has since made a bright start to the current campaign.
Indeed, the Egypt international has recorded 12 goals and nine assists in 14 games this term, including 10 strikes in just nine Bundesliga matches to help Frankfurt climb up to third in the table.
Marmoush's exceptional form has understandably caught the eye of a number of top European clubs, with Premier League trio Liverpool, Manchester United and Arsenal believed to be among those keeping tabs on the attacker.
A recent report claims that Arne Slot's side have 'officially expressed' an interest in Marmoush as they look to steal a march on their English top-flight rivals.
Bayern move ahead of Liverpool in Marmoush race?
According to Sky Deutschland reporter Florian Plettenberg, the Reds indeed have a 'serious interest' in Marmoush, but they will face stern competition for his services from German giants Bayern Munich.
Plettenberg claims that Bayern 'definitely' have Marmoush on their radar ahead of next summer and have already held 'some initial, informal talks' over a possible transfer.
Although no agreement has been reached between both clubs and no official negotiations have taken place, Bayern chief Max Eberl is said to be an admirer of Marmoush and will continue to monitor his development at Frankfurt.
Frankfurt are under no immediate pressure to cash in on their No.7, who is under contract until 2027 and is valued by the Eagles between €50m (£41.9m) and €60m (£50.3m).
Bayern's interest in Marmoush comes at a time when Leroy Sane has been linked with a possible exit from the Allianz Arena amid reported interest from Premier League quartet Arsenal, Chelsea, Man United and Newcastle United.
Liverpool, meanwhile, are understood to have identified Marmoush as a potential replacement for fellow Egyptian Mohamed Salah, whose future at Anfield remains uncertain as he is due to see his contract expire next summer.