England have left Nick Compton out of their Ashes warm-up squad to face Essex, explaining they see Joe Root as "currently the best opening partner for Alastair Cook".

Compton has opened for England in their last nine Test matches, against India and New Zealand, but could muster only 39 runs in four innings in their two-match home series with the Kiwis last month.

He still has an opportunity to prove his credentials afresh in a four-day match between his county and Australia, set to start in Taunton on Wednesday, but will not feature for his country against Essex at Chelmsford next weekend.

"We believe Joe Root is currently the best opening partner for Alastair Cook, and he will open the batting against Essex," said national selector Geoff Miller. "Joe has performed well for Yorkshire at the top of the order earlier this season, and during his international career so far has proven to be very adaptable in all three formats and relished the challenge of international cricket."

England have named a 14-man squad for the match, beginning on Sunday, and are expected to finalise a 12 or 13 six days later for the first Ashes Test at Trent Bridge on July 10.

Boyd Rankin is the only member of the squad to face Essex who has yet to play for England in any format. The tall Irishman joins five other pace bowlers in the squad - James Anderson, Tim Bresnan, Stuart Broad, Steven Finn and Graham Onions.

Rankin, Onions and a fit-again Kevin Pietersen are the only players selected who were not named in either squad to face New Zealand at the start of this summer.

First-choice off-spinner Graeme Swann missed all but one of England's matches in the Champions Trophy, which concluded when they lost the final to India on Sunday.

Pietersen, out of action since March because of bruising behind his right knee, has just made a spectacular comeback with Surrey - hitting an unbeaten 177 not out against Yorkshire in his first innings of the summer.

England squad: AN Cook (Captain), JM Anderson, JM Bairstow, IR Bell, TT Bresnan, SCJ Broad, ST Finn, G Onions, KP Pietersen, MJ Prior (wkt), WB Rankin, JE Root, GP Swann, IJL Trott.