Penkywicz, a National League One Player of the Year nominee in 2007 and one of the outstanding talents outside Super League, will be sidelined for at least six weeks after undergoing surgery to pin the broken scaphoid that has hampered him since the round two win at Dewsbury at Easter Monday.
His place against the Vikings will be taken by Gleeson, the 26 year old former Warrington and England player who only linked with Fax a little over a week ago.
"It was getting to the point where I had to have the op, and it will certainly be a lot easier for us to cope now we have signed Mark," said Penkywicz, who destroyed the Vikings as Fax won at the Halton Stadium in early June.
"I have played against him a few times in Super League and there is no doubt he is a quality player.
"He goes well that level so he should be a great addition to the squad.
"I have been really struggling - I can't tackle and can't pass, so there's not much left after that - and by having surgery now there is at least a chance I will be back for the play offs."
Penkywicz's endorsement was echoed by coach Matt Calland, who is likely to rotate Gleeson with on loan Wigan youngster Thomas Coyle.
"Mark has looked really good in training this week," confirmed Calland.
"He's quick out of dummy half and has a great attitude.
"Hooker is not an easy position to slot in to, and it will take him time to learn the calls and how people play, but I am excited about seeing him on the field."