Ibrox side Glasgow Rangers are set to take on Hibernian tomorrow evening.
Rangers have had a busy fixture schedule of late, and both McCrorie and Pena have featured heavily.
Murty is now fearful of burning his players out, with McCrorie and Pena said to be two of his main concerns.
“We have got people that have played a lot of games in a small space of time so we are looking at them and making sure that we don’t overload them, but if we use them they are ready to go at full capacity,” Murty said.
“If they are not, that is not fair on them. We have to make sure, going into a hostile environment, that everyone has got the full capacity to go and cope with that.”
Pena and McCrorie missing out for Rangers would be a blow for Murty’s side, as the pair have been in good form recently.
Rangers have won their last three matches in the Scottish Premiership table, to move into second spot in the table.
Rangers are now the slight favourites to win against Hibernian, but Neil Lennon’s side are also in good form.
Hibs are unbeaten in three matches, and came from 2-0 down to pick up a point against Celtic in their last match.
When Hibs met Rangers earlier in the season, Lennon’s side won 3-2 at Ibrox.
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