Rennes let three strikers leave earlier this year and, with Victor Hugo Montano out injured for a month, must rely on 22-year-old Jires Kembo-Ekoko up front when they entertain Montpellier on Saturday.
"If we recruit a good striker (in January's transfer window) and we do not have too many players injured we can target a top-five finish," Antonetti told the club's website.
Rennes sold France's Jimmy Briand to Olympique Lyon in June before off-loading Ghanaian Asamoah Gyan to Sunderland and Guinea's Ismael Bangoura to Al-Nasr.
"In September Asamoah left for England and then an offer came from Qatar for Bangoura," said the coach.
"(General manager) Pierre Dreossi asked me, 'what do we do?'. If I had wanted to play it safe I would have said let's keep Bangoura but I said I'm convinced Kembo can do as well as Bangoura.
"He now must mature into a reliable striker," added Antonetti whose team have 19 points from nine games and lead second-placed St Etienne by two points.
Coach Didier Deschamps has reshuffled Marseille's defence after Brazilian centre-back Vitorino Hilton picked up a groin injury last week.
Gabriel Heinze moved from full-back to central defence for Tuesday's 1-0 Champions League win over Zilina, meaning Stephane Mbia was shifted to midfield.
"It's been a year since I last played in this position but I play where I'm asked to play," said Mbia.
