After sitting out the French adventure, Jenkins is now likely week to return to the side for the Magners League derby with the Scarlets on Friday, October 22.
Scotland fly-half Dan Parks is also expected to miss the European encounter, while Martyn Williams will go before an ERC disciplinary panel later today. If found guilty, the 95-cap Test veteran faces a spell on the sidelines that could yet affect his international involvement this autumn.
But in some good news for the Blues and for Wales, fellow international Tom Shanklin has recovered from a bang to the head and is expected to feature alongside Casey Laulala in midfield.
A trio of Welsh internationals are expected to fill the absentees' boots: John Yapp coming into the front row for Jenkins; Ceri Sweeny starting instead of Parks at No10, and Sam Warburton replacing Williams in the back-row.
"They both had scans yesterday and it's looking extremely unlikely that they will be available," said Blues director of coaching Dai Young, referring to the injuries to Jenkins and Parks.
"Gethin's probably nearer to a return than Dan. He rolled his ankle, it's nothing long-term. If he's not back for this week, I'm sure he will be next week.
"Dan's a little further away with a foot injury. He could be out for two weeks but he's walking about on it. We will know more with the results but we're not going to put any players at risk.
"Dan and Ceri get on really well and support each other. They both want to play and Ceri has never let us down.
"They are two different players and have different strengths and weaknesses. I'm sure Ceri will be eager to step up this week and keep the jersey."
The Blues are also training without Wales legend Williams, with his game preparations distrupted by today's hearing in Dublin.
"We're pretty much planning without Martyn this week. We trained yesterday, have a team run on Thursday and that's pretty much it so we have crack on without him," added Young.
"We all know he's not a dirty player. He is recognised the world over as someone who plays fairly. I don't think anyone would accuse Martyn of wrong doing on a regular basis."