The 23-year-old had enjoyed a successful loan spell at Valenciennes, where he scored nine goals in 16 appearances in 2014, but failed to find his scoring boot last season at Trabzonspor.
He made only 18 appearances, including nine starts, without a goal at the Turkish club. However, Rennes coach Philippe Montanier claims the former BK Hacken striker would be useful at Roazhon Park, according to reports.
Despite signing five new players, Montanier is keen on recruiting the Ghanaian as he looks forward to improving his team’s ninth position from last season.
Warris was linked to Manchester United and Stoke City last January, with the Red Devils sending scouts to monitor him but no deal was reached.
He made his debut with Ghana against Chile in 2012 and has been capped 18 times scoring four goals.