England have called up Essex youngster Alastair Cook as batting cover for injured captain Michael Vaughan.
Vaughan is awaiting the results of a scan on his injured knee which could rule him out of the three-Test tour of Pakistan.
The 31-year-old is a serious doubt for the first Test which starts in Multan on Saturday and there are fears he may have to return to home for surgery if the injury proves serious.
No definitive decision is expected to be made today but England - who are also expected to lose Andrew Strauss for the third Test as he returns home for the birth of his first child - have decided to summon Cook.
Left-hander Cook, a former England Under-19 captain, had emerged as one of the leading contenders for a call-up when Vaughan twisted his knee on Monday as Rob Key and Owais Shah both require surgery this winter.
The 20-year-old caught the eye with a double century in a tour match against Australia this summer and had been selected for this winter's National Academy squad.
Marcus Trescothick is on standby to captain the side but England are still hoping Vaughan will be able to play some part on the tour.
Chairman of selectors David Graveney said: "Alastair Cook has been called into the squad as we felt we needed an opening batsman to provide cover not only for Michael Vaughan, but also for Andrew Strauss who is expected to fly home before the third Test to attend the birth of his child.
"Alastair had an outstanding season for Essex last summer, is a member of our National Academy squad this winter and we believe he has the potential to succeed at international level."
England have also made additions to their one-day squad by adding veteran spinner Shaun Udal - who is currently with the Test party - and Worcestershire seamer Kabir Ali.
