Portsmouth manager Paul Hart's controlled delight at his side's vital 1-0 home win over Bolton was tarnished by an injury to midfield star Niko Kranjcar.
The Croatia international is almost certainly out of their visit to Manchester United on Wednesday, while Hart also has a doubt over the fitness of defender Younes Kaboul.
A downbeat Hart said: "It looks like a twisted ankle but it is still a blow for us because he's an important player for us, especially in a small-ish squad."
He added: "I certainly wouldn't expect him to be available for the game at United on Wednesday and it could be a worry long term."
Kranjcar missed a large chunk of the season following an ankle operation in AugustÂ but has returned to be a key player for Pompey.
Just two minutes after he was forced off, though, his replacement Nadir BelhadjÂ used his first touch to fashion a viciously inswinging corner from the right and, when the ball eluded keeper Jussi Jaaskelainen, fellow substitute Kanu claimed a scoring final touch.
It was Kanu's first Premier League goal of the season and Hart said: "I didn't really see what happened for the goal but we'll take it.
"I'm told Kanu has claimed it but it doesn't matter to me who scores as long as it is us and I thought we deserved it."
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