The Newcastle United boss was pictured winking at the West Bromwich Albion striker during their 1-0 victory.
Berahino was a half-time substitute for West Brom at St James' Park, but was unable to influence the game in his side's favour against a resilient Newcastle defence.
Newcastle made extensive efforts to try to sign Saido Berahino in the January transfer window, with The BBC reporting they bid £21 million.
West Brom held firm and decided to keep the striker, and after Newcastle's win at the weekend they might just need him.
The Baggies are in 14th place, just six points ahead of the relegation zone, and while they should have enough to avoid the drop, selling Berahino to a competitor, without leaving any time to re-invest it, could have been a bad move.
Providing Newcastle retain their Premier League status, there is every chance they may renew their interest in the summer.