"The initial scan carried out in Lahore say he is out of the tour because he might have to undergo surgery for the groin problem," Pakistan Cricket Board director of cricket operations Saleem Altaf told Reuters on Thursday.
Pakistan have already lost fast bowler Shoaib Akhtar for the four-Test series because of an ankle stress fracture.
"The initial reports are not very encouraging. It is a pretty tricky situation. We are going for a second opinion from the head of our medical commission," Altaf said.
He said Rana would be out for three months if surgery was necessary.
Rana, 28, has been one of Pakistan's most potent bowlers in recent series taking 16 Test and 77 one-day wickets.
Last summer he took 88 wickets for Sussex and this year in five matches he has claimed 34 wickets at 15.29.
"We feel the report is sitll inconclusive. But if required we might even send him to England for the surgery," Altaf said.
Pakistan play four Tests and five one-day internationals in England with the first Test starting at Lord's on July 13.