Alan Thompson and Chris Sutton will undergo fitness tests before Martin O'Neill finalises his plans for their Champions League Group A match against Anderlecht tomorrow.
The English duo flew out to Belgium with the rest of the first-team squad this morning in the hope they would shake of hamstring problems.
Sutton was left out of the 5-0 hammering of Hearts at Parkhead on Saturday while Thompson was forced to hobble off after suffering a recurrence of the injury sustained at Ibrox.
But O'Neill was hopeful the influential pair would recover in time as they would both be expected to start the game if they were fit.
But where Sutton would play remains a big mystery with Henrik Larsson and John Hartson doing so well in attack and the defence conceding just one goal in their last five games.
The former Blackburn Rovers star won the man of the match award with his superb display in defence against Rangers and he could slot straight back in for Stanislav Varga.
The Slovakian picked up an ankle injury against Hearts, but O'Neill does not think it is too serious and is expecting him to be fit in time.
Such is the form of last season's beaten UEFA Cup finalists that Joos Valgaeren and Johan Mjallby - who did not travel - are not being rushed back after recovering from injury.
PROVISIONAL SQUAD: Hedman, McNamara, Varga, Valgaeren, Agathe, Lennon, Sutton, Petrov, Thompson, Larsson, Hartson, Miller, Douglas, Gray, Sylla, Petta, Maloney, Balde, Smith, Kennedy.