John Stones
John Stones is one of the centre-backs being monitored by Jose Mourinho despite United confirming the arrival of Eric BaillyGetty

Jose Mourinho is set to continue his spending spree after Manchester United confirmed Eric Bailly as their first signing of the summer. The former Villarreal defender is tipped to become one of the best by the Portuguese manager after he arrived on the back of a successful campaign with the Yellow Submarines.

According to the Manchester Evening News, however, the Red Devils boss is planning to bring in yet another central defender as he is aware that the young Ivory Coast international could struggle to adapt to the demands of the Premier League. Bailly has completed just one full season in the La Liga, which makes him very inexperienced to immediately form a partnership with Chris Smalling at the heart of the back four.

Daley Blind was the England international's regular partner last season, but Mourinho is likely to want a more imposing centre-half with the Dutch utility player more likely to be used as a backup at left-back or in midfield. The former Ajax midfielder is keen to fight for his place, but could find game time limited if another defender is brought in by Mourinho. Another player facing uncertainty over his future is Phil Jones, who has struggled with form and fitness throughout the 2015/16 campaign making just seven appearances in the league.

The 20-time English champions have been linked with moves for a number of high profile defenders with Raphael Varane, Aymeric Laporte and John Stones on top of the list. The former will be tough to prise away from Real Madrid, despite the Frenchman struggling for regular game time, while the latter two have also courted interest from United's rivals Manchester City and Chelsea respectively.

Mourinho is a big admirer of the Everton defender and made a move for him last summer, when he was at Stamford Bridge and is likely to return with a bid during the upcoming summer transfer window. The Toffees, according to the Independent, will reject the bid yet again, but after finishing in 11h place in the league last season, the defender is likely to force a move if one of the Premier League big guns come calling.