Chelsea's Portuguese defender Ricardo Carvalho could be out for up to eight weeks after injuring his back in Sunday's 1-1 home draw with Everton.
Carvalho is the latest key player ruled out for Chelsea
Portugal national team doctor Henrique Jones examined the injury and instantly ruled him out of their Euro 2008 qualifiers with Armenia and Finland.
"It was not serious but he should rest for at least eight weeks," he said.
If confirmed, it will be another blow for Chelsea who already have Petr Cech, John Terry and Paulo Ferreira injured.
One grain of consolation is England left-back Ashley Cole's return to fitness after an ankle problem.
After Sunday's draw at Stamford Bridge, which leaves Chelsea five points behind Premier League leaders Arsenal, Grant conceded: "We have too many injuries.
"It is not easy to play without all the back four and goalkeeper from the last few months.
"This is the reason we have a big squad but it is unusual."