Premier League 2017/18: 5 biggest surprises of the season

#4 The Alexis Sanchez - Henrikh Mkhitaryan swap deal

The two players in action for their new clubs

The January transfer window was an exciting one that also some heavy deals completed. Arguably the biggest surprise deal of the window was the exchange of Alexis Sanchez and Henrikh Mkhitaryan.

The Chilean left Arsenal for Manchester United as his Gunners contract was winding down while the Armenian joined the Gunners in a swap deal that swept the football world.

Jose Mourinho signed Sanchez and beat rival Pep Guardiola and Manchester City to land the player. In what the United boss described as a once-in-a-lifetime deal, Sanchez is a fine addition to the ranks at Old Trafford.

Mkhitaryan did not settle like he had hoped he would at United, with irregular game time and a style of play that just didn't suit the player. He has, however, settled into this Arsenal side and has been much more expressive on the ball with the North London club - a sign of better things to come.