LONDON • Chelsea have had a second offer of £26 million (S$56 million) for John Stones turned down by Everton while Manchester United have also made known their interest in the young defender.

The Red Devils have contacted intermediaries working on Stones' behalf to make him aware that they would welcome him at Old Trafford. But they have not yet made a formal approach to Everton.

As such, Chelsea are at the front of the queue for the signature of the 21-year-old.

Blues manager Jose Mourinho sees Stones - who has four years to run on his Goodison Park contract - as a potential long-term successor to John Terry.

Although the Chelsea captain remains integral to the club, Mourinho believes that now is the time to test Everton's resolve.

Were Chelsea to wait for another season, the England international's price would surely rise.

As it is, Everton will refuse to sell him for less than £30 million.

The sum would represent quite a mark-up for a player whom they signed for £3 million from Barnsley in January 2013.

Everton are also believed to be interested in the possibility of including a player in any potential deal.

The Merseyside club rejected Chelsea's opening bid of £20 million last week and gave short shrift to Tuesday's follow-up.

Manager Roberto Martinez has identified the man he would like to replace Stones in the event of his departure. He is thought to have made Virgil van Dijk, the Celtic and Netherlands central defender, his priority target should Chelsea prove too difficult for Stones to resist.

The 24-year-old is likely to cost about £10 million, although Everton could face competition from Southampton for his services.

Martinez has already lost veteran defender Sylvain Distin to Bournemouth this summer, and is keen to add at least a midfielder and a forward to his ranks. THE TIMES, LONDON, THE GUARDIAN