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.
RELIABLE STRIKER
"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.
On Sunday, champions Olympique Marseille travel to Lille.
Marseille are fourth, two places higher than Lille who suffered their first league defeat of the season at Lyon last weekend.
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.
St Etienne will be without striker Gonzalo Bergessio, who was sent off in the 2-1 defeat at Nice last week, when they host mid-table Caen on Saturday.
Third-placed Paris Saint-Germain could be without Mateja Kezman, who has stomach problems, at home to AJ Auxerre on Sunday.
Lyon, who have won their last two games following a miserable start to the season, also visit bottom club Arles-Avignon on Sunday.
