The duo only joined the Championship side last week in a bid to impress the Forest manager, with Fanni receiving 45 minutes of action in Saturday's friendly against Premiership side Tottenham Hotspur.
Kinnear has decided he has seen enough of Fanni and Sarr (pictured) and will not take his initial interest in the Lens players any further.
"They are with decent clubs in France, but they're not for me," Kinnear told the club's official website.
"They haven't done enough in the time they have been with us and I believe I can get better."
