Byrne has had a torrid time with injury since limping out of the Lions opening Test with South Africa in the summer, twice being sidelined with ligament damage in his right foot.

The 29-year-old has made just four appearances for Ospreys this season as a result and missed all of Wales’ autumn internationals against New Zealand, Samoa, Argentina and Australia.

Byrne last featured in Ospreys 32-32 draw with Leicester in the Heineken Cup in October and despite being expected to face Scarlets on Boxing Day, Holley won’t be rushing him back.

“He has been struggling but there is nothing like match fitness and playing which is why we have to take it steady and slow as we have with the other injured guys,” said Holley.

“I envisage Lee not playing 80 minutes – but he is in good spirits, pain-free and looking forward to getting back on the field.

“He is looking very lean and fit – although I don’t suppose his lungs will tell you that looking at the sessions he has been doing in rehab.”