Cape Town - Chelsea's improved offer for Everton's England international defender John Stones has been rejected, according to reports.
Everton have dismissed Chelsea's £26 million offer, reports ESPNFC.com.
Sport24 reported that a second bid for Stones was brewing after the Toffees turned down the first offer of £21 million last week.
Stones has four senior England caps to his name and signed a new five-year contract with Everton last season, allowing the Merseyside club to dig in their heels regarding the possible transfer.
English media has speculated that Stones is open to leaving the club after being lined up as John Terry's long-term replacement at Stamford Bridge.
Everton have reportedly set Stones' valuation at £30 million.
Neither club has opted to comment on the second bid.
Manchester United and Manchester City are monitoring the situation and may decide to enter the race for the 21-year-old star.
Stones joined the Toffees from Barnsley for £3 million in January 2013.