Springbok No 8 Duane Vermeulen arrived in Belfast on Monday to join up with his new Ulster team-mates.
Vermeulen signed for the Irish club from the Bulls back in September but couldn't join them before his Test duties with the Springboks were completed.
The 35-year-old was due to play for the Barbarians against Samoa in London over the weekend but the game was cancelled due to positive Covid-19 cases in the camp.
Ulster forwards coach Roddy Grant told RTE Sport that he's not sure whether Vermeulen will be available to tackle Welsh outfit Ospreys in Swansea on Saturday, but said they were delighted to see the World Cup winner arrive.
"He's in Belfast and going through the protocols of coming in. There are a few things to that. We're just getting through it today, we'll see how we go," Grant said on Monday.
The coach added that he was looking forward to coaching a "world-class" player like Vermeulen.
"It (Vermeulen's signing) was announced a while ago but it's like Christmas, when it comes it's exciting, certainly for me as a forwards coach," he said.
"There are multiple layers of this. Guys say he's a brilliant bloke a great leader, obviously has a huge presence.
"Young guys will pick up that, how he carries himself, how he talks, how he plays, he's so consistent, he's got massive plays."
Ulster upset Leinster 20-10 in Dublin last weekend, which was their first win at the RDS Arena since 2013.
They are currently second on the overall United Rugby Championship table, just behind Leinster on points difference.