Portsmouth may be forced to recall Andy Griffin from his loan spell at Stoke.
Griffin could head back to the south coast with Stefanovic ruled out
Skipper Dejan Stefanovic limped out of the 1-0 Newcastle defeat at half-time and will undergo knee surgery which he has repeatedly postponed until now.
And his replacement, Matt Taylor, struggled through the closing stages with a back problem he picked up.
Boss Harry Redknapp said: "I've not got a left-back on the books. We need to be at full strength to do okay. If we lose three or four, we're in real trouble."
Following the St James' Park reverse, Pompey have now lost five successive matches on the road and face a midweek trip to Liverpool.
After that come home matches against Aston Villa and Everton before a trip to Arsenal.
That run of matches will severely test their strength following a solid start to the season that sees them sitting fourth after 14 games.
"Matty is struggling with an injury to his back and Dejan is going in for an operation," Redknapp confirmed.
"We have lost Glen Johnson who was also very important to us and you really need your full squad to be fully effective.
"But on the plus side we have 23 points and are in a healthy position because of the great start we made."