The Conakry club have offered no explanation for the shock move after widely experienced Neveu masterminded a largely impressive group campaign.
Horoya finished second in Group B behind trophy-holders Esperance of Tunisia, but four points ahead of Orlando Pirates of South Africa after beating them 2-1 last Saturday.
Previous coaching assignments of Neveu included handling the national teams of Niger, Guinea, the Democratic Republic of Congo and Mauritania. Â
He has been replaced by France-born Didier Gomes da Rosa, whose best achievement in Africa was guiding Cameroonians Coton Sport to the 2014 CAF Confederation Cup semi-finals. Â
Horoya president Antonio Souare has publicly demanded that the team reach the Champions League semi-finals this season after losing to Egyptians Al Ahly in a 2018 last-eight tie.
He is set to be disappointed, though, as twice champions Wydad should prove too strong over two legs under the guidance of veteran Tunisian coach Faouzi Benzarti. Â
The draw in a Cairo hotel paired Esperance with CS Constantine of Algeria, surprise  qualifiers from Group C at the expense of Club Africain of Tunisia and Ismaily of Egypt.
Record eight-time champions Ahly will face Mamelodi Sundowns of South Africa in a repeat of the 2001 final won convincingly by the Cairo Red Devils.
Tanzanian club Simba, another surprise qualifier, face five-time trophy-holders TP Mazembe from the Democratic Republic of Congo.
Quarter-finals
CS Constantine (ALG) v Esperance (TUN, holders)
Mamelodi Sundowns (RSA) v Al Ahly (EGY)
Horoya AC (GUI) v Wydad Casablanca (MAR)
Simba SC (TAN) v TP Mazembe (COD)
First legs: April 5/6, second: April 12/13
Semi-finals
Horoya/Wydad v Sundowns/Ahly
Constantine/Esperance v Simba/Mazembe
First legs: April 26/27, second: May 3/4
Horoya/Wydad/Sundowns/Ahly v Constantine/Esperance/Simba/Mazembe
First leg: May 24/25, second: May 31/June 1