Former Manchester City frontman Balotelli has been rumoured to be in discussions with the club, but Tanner recently told Jonathan Tannenwald of the Philadelphia Inquirer there have been no such talks.
Tanner, who is on a scouting trip in Europe, dismissed the speculation and said: "There is not a piece of truth in that story. I don't know why this is coming up. I never was in touch with him."
Balotelli, 28, arrived at the Allianz Riviera on deadline day in August 2016 and enjoyed a prolific first two seasons, the likes of which he hasn't enjoyed for years.
But after scoring 45 times in his first 68 appearances for the club, the Italian has hit a stumbling block in 2018-19 and can't find the back of the net, per WhoScored.com:
Union would in all probability struggle to meet Balotelli's wage demands, as well as the fee it would likely take to sanction his move from his French employers, who are in the middle of their Ligue 1 campaign.
However, Nice could see this as an opportunity to cash in and potentially make profit from a temperamental player who was brought in as a free transfer.
Balotelli's rejuvenation since moving to France may lead one to believe the former Inter Milan bad boy has changed his ways altogether.
However, Nice coach Patrick Vieira—who played alongside the forward at Inter and City—spoke to the media in October and hinted the opposite could be true: "Mario was already the man he is now when he was 16 years old. I think he'll be the same at 45."
Balotelli was linked with an exit over the summer, but journalist Andy Brassell nodded to Vieira's impact in preventing that:
The Philadelphia Union made it to the knockout stages of this season's play-offs before losing to New York City FC, and Tanner's denial suggests Balotelli won't arrive to help their cause in 2019.