Luciano Spalletti has called on Inter midfielder Radja Nainggolan to stop being distracted by matters outside of football.
Spalletti also coached the 30-year-old Belgian midfielder at Roma and brought him to San Siro this year.
Nevertheless, that close bond does not prevent him from taking a strict approach when the combative Nainggolan steps out of line.
"We love him, he is a sensitive boy and he has all the qualities of the person who behaves correctly. But sometimes even the father grumbles with his son," Spalletti told reporters.
"Radja is attracted to other things and if you put too many things in front of football you do not win.
"He has three or four of things he puts in front of football and some of them have to be taken away."
Back-to-back wins to close 2018 mean Inter lie third in Serie A, five points shy of Napoli in second.
The Nerazzurri's next league game is against Sassuolo on January 19.