The influential winger, who was among the scorers in Stoke's 5-0 semi-final victory over Bolton, tore a hamstring half an hour into Tuesday's 3-0 win against Wolves.
With so little time before their second trip to Wembley on May 14, Etherington's chances looked slim, but Pulis is certainly not writing him off yet. The Welshman said: "He's had the scan, he's got a torn hamstring and we'll know better in seven days how much chance he's got. He'll be treated and looked after as best we can."
"We've got to do our damnedest in the next seven days to put him in a position where we give him the best opportunity to play in the cup final. His leg could be hanging off and I wouldn't rule him out."
The injury to Etherington, who was part of the West Ham team beaten in the FA Cup final by Liverpool five years ago, is the latest blow for Pulis after Ricardo Fuller and Danny Higginbotham were ruled out of the City clash.
Pulis added: "We've been very unfortunate losing Higginbotham, Fuller and then Matty picking that injury up. It's going to be a difficult enough game for us anyway, but to lose three very influential players - if Matty doesn't make it - is going to make it doubly difficult."
Higginbotham will miss the start of next season after suffering cruciate ligament damage earlier this month while Fuller underwent an operation on Wednesday on a ruptured Achilles he sustained during last weekend's draw with Aston Villa.
Pulis said: "Ric's going to be three or four months, which is a massive blow to him and a massive blow to us. He had the operation and they tell me everything's going fine."
Source: PA
Source: PA