Halfpenny, who spent last season in England with Harlequins, signed while recovering from a calf injury.

The 36-year-old won the Challenge Cup and Anglo-Welsh Cup during his first spell at the Arms Park between 2007 and 2014.

The full-back is working with the Cardiff kickers and will soon be available for selection.

“He is almost back to full training so hopefully in the coming weeks he will be joining us on the pitch doing the sessions, then we can take it from there. There’s no doubt that he will add value to the outside backs,” said Van Zyl.

Cardiff name their team to face Munster, who won impressively at Scarlets last Saturday, at midday on Friday, but will be without influential centre Thomas after his 20-minute red card.

He is banned for at least two games but will return against Dragons if he completes the World Rugby coaching intervention programme, also dubbed “tackle school”.

After head coach Matt Sherratt left on the eve of the season to join Wales, Van Zyl is temporarily leading a coaching team that also features his fellow assistants Gethin Jenkins, Jonny Goodridge and Scott Andrews.

“Nothing has changed and we have settled in,” said the South African. “The coaches have grabbed the opportunity, we all enjoy what we do and we just have a little bit more responsibility.”