Newcastle United have confirmed the permanent transfer of Kevin Mbabu to BSC Young Boys.
The Magpies have received an undisclosed fee for the full-back, who spent last season on loan at Stade de Suisse.
Mbabu's exit follows on from the news that Vurnon Anita, Sammy Ameobi and Haris Vuckic would not be offered new deals this summer, as Rafa Benitez oversees a complete squad overhaul ahead of United's return to the Premier League, which begins with a home game against Tottenham on August 12.
Mbabu was an integral part of the Young Boys side, under Adi Hutter, who finished second in the Swiss Super League last season.
His chances at United were always going to be limited with Benitez looking to add up to four new defenders to his ranks before the end of the summer window.
The 22-year-old defender joined Newcastle from Servette in January 2013, making his bow in a Capital One Cup defeat to Sheffield Wednesday in September 2015.
Three days later he was a stand out performer for United in the top flight against Chelsea, marking Eden Hazard out the game on his Premier League debut.
In total Mbabu made five appearances for United.
A club statement, confirming his exit, said: "The club wishes him well for the future."
Nottingham Forest are said to be looking into the prospect of signing Ameobi, who spent much of last season on loan in League One with Bolton Wanderers, on a free.
Vuckic on the other hand is likely to head to the continent, with clubs in Holland and Belgium weighing up a move.
The attacking midfielder had a spell on trial at FC Twente earlier this season.
News is still awaited on whether Yoan Gouffran, another player out of contract, has come to an agreement on a contract extension at St James's Park