Portsmouth forward Brett Pitman and defender Lee Brown could return for Thursday's play-off second leg against Sunderland, according to Blues boss Kenny Jackett.
Pitman and Brown both missed Saturday's 1-0 defeat at the Stadium of Light, with the pair nursing knee and Achilles injuries respectively.
And Jackett has revealed the duo will return to training on Wednesday, one day before the huge clash on the south coast.
"They were outside running but not in full training today," said Jackett when asked about the pair.
"Full training for them will be tomorrow, which will obviously then be their fitness test, if they complete and do the session, they'll be available to play.
"If not, then obviously it will mean opportunities for other people.
“It’s effectively a fitness test to see whether they can play on Thursday,"
Pitman and Brown have been key players for Pompey this season, with the former netting 11 goals and proving five assists in all competitions this season.
Brown, too, has played a key part this term, featuring in 44 of Portsmouth's 46 League One games at full-back.
Pompey have already sold their full allocation for the game at Fratton Park, when the Blues will need to overturn a 1-0 deficit.
And Jackett believes the crowd can play a big part in the tie, with a place at Wembley up for grabs.
“We’ll need a performance of enthusiasm and quality, while recognising that there’s an opportunity for one of these four sides to get into the Championship," added Jackett.
“There will be a passionate crowd inside Fratton Park and we have to bring them into play.”