Chelsea: Barcelona monitoring Jose Mourinho's top centre-back target John Stones

Chelsea may need to battle with Barcelona to secure the services of Everton defender John Stones after Mundo Deportivo reported that the Champions League winners are also closely monitoring the development of the England international centre-back. The 21-year-old defender was heavily linked with a move to Stamford Bridge during the summer transfer window after José Mourinho earmarked him as a priority to make him John Terry's long-term replacement.

Stones even handed in a formal transfer request to force through a move to London in the last days of the transfer window, but the Toffes managed to keep him at Goodison Park – rejecting four different bids for the England starlet, including one of £38m ($58.2m).

Daily Mirror recently claimed that Chelsea are ready to back the Portuguese boss with a fresh bid for the Everton centre-back during the January transfer window in order to address the problems in the Blues back-line during their poor start to the campaign.

But Mundo Deportivo suggests that the Premier League giants may face competition from Barcelona. The Champions League winners have struggled to find a proper partner to Gerard Piqué since club legend Carlos Puyol hanged his boots – having conceded nine goals in the seven La Liga first games of the campaign.

Javier Mascherano has been forced to fill the role in recent seasons but he is already 31-year-old and recently refused to hide that he still feels more comfortable in the middle of the park. Jeremy Mathieu has failed to make the impact expected since his arrival from Valencia in the summer of 2014 while Thomas Vermaelen keeps struggling with injuries. Further, Marc Bartra considered to move away during the summer to secure more playing time somewhere else, and with the situation unlikely to change this season he may finally leave the Camp Nou.

Mundo Deportivo also reports that the club are monitoring four young centre-back ahead of a future move. The first name on Enrique's shopping list short-list is Aymeric Laporte but with Athletic Bilbao refusing to negotiate his departure Stones, Paris Saint Germain Marquinhos and Atletico Madrid's José Giménez are also in their radar.