The Scottish champions sold Dembele to Lyon in 2018 for a fee in the region of £19m.
The 26-year-old has since been on the books at the French giants, making 87 goal contributions in 156 appearances; Dembele had a loan stint at Atletico Madrid earlier this year.
Now four-and-a-half years later Dembele has been linked with a return to his old club in Scotland, though McManus is not too hopeful about the prospect of him returning to Celtic Park.
“I think Celtic need to strengthen”, McManus said on PLZ Soccer.
“I have seen somebody linking [Moussa] Dembele back to Celtic. I think he is available for £5m or £6m.
“He has had a lot of injury problems at Lyon and Atletico Madrid.
“[There is] talk about him coming back to Celtic but I don’t see that one happening.”
The need for Celtic to sign a striker is genuine though, in spite of the presence of the Kyogo Furuhashi and Georgios Giakoumakis duo, McManus feels.
“I think Celtic will definitely be in the market for a striker.
“I think that is one area they need to strengthen.
“They have got Kyogo and Giakoumakis, but I think they need one more.”
Celtic have scored as many as 50 goals over the course of the 15 league games they have played so far this season, conceding just 13.
