Stoke boss Tony Pulis' plan to sign Andy Griffin on a permanent deal looks set to fall through.
The defender made a big impression during his three-month loan spell with The Potters earlier this season, and Pulis had hoped to tie him to a long-term contract at The Britannia Stadium.
Griffin had also been eager to secure a move to Stoke, the club where he started his career.
However, an injury crisis at Portsmouth has left Harry Redknapp short of options and unable to let Griffin leave.
"We've got only two spare defenders," Redknapp explained.
"Andy Griffin wants to go back to Stoke and Stoke want him, but I can't let him go."
Pulis accepts that Griffin is needed at Portsmouth, but is not resigned to losing him just yet.
"I understand Portsmouth's problems," Pulis told The Sentinel.
"All we can do is wait for them to come to us to hopefully do a deal."