Ulster have said Duane Vermeulen will be monitored ahead of any potential debut in Saturday's Champions Cup opener against Clermont Auvergne.
The back row, 35, arrived in Belfast last week but tested positive for Covid-19 after an outbreak in the Barbarians' squad.
Ulster said the Springbok World Cup winner is "completing his graduated return to training programme".
Vermeulen's fitness to play will be monitored ahead of the game.
Front row trio Bradley Roberts (ankle), Marty Moore (concussion) and Tom Stewart (foot) sustained injuries during Saturday's defeat by Ospreys and are unavailable for Ulster's Champions Cup opener.
They join Jacob Stockdale, Luke Marshall, Will Addison, Iain Henderson, Cormac Izuchukwu and Jordi Murphy on the current injury list.
"It's quite a complicated one this week," Ulster head coach Dan McFarland said on Monday.
"It would definitely be great, if hypothetically, Duane were to be fit and up and running. It would be very smart to have him in the team."
Ulster announced that Vermeulen was isolating last Tuesday having arrived in Belfast before testing positive, following South Africa's autumn Tests and the Barbarians game with Samoa which was called off at the 11th hour following a positive case in the squad.
He subsequently missed the province's URC defeat by Ospreys.
"We've got WhatsApp groups here and there, different groups, different involvements there, so he's been added to all those groups," said lock Kieran Treadwell.
"I think he's been watching the meetings and watching training in his room, so he's been as involved as he can be really."
'We'll have to be up in Clermont's faces'
McFarland has urged Ulster to play as a "collective" against Clermont while admitting that "simple, slow ball is not going to cut it" against the French side.
The province's disappointing loss in Swansea dented the momentum gained from a rare away win over Leinster.
"The team has got to work as a collective," said McFarland.
"Both sides of the ball, especially on the defensive side of the ball we have to bring collective pressure.
"That means consistent movement throughout the pitch and getting off the line so we can suffocate them."
Having ended November by claiming a first away win over Leinster since 2013, Ulster slumped to a disappointing 19-13 reverse to Ospreys in Swansea on Saturday, with McFarland lamenting the province's inability to "get any quick ball going" during his post-match remarks.
Speaking on Monday, however, the Englishman appeared more upbeat about his side's performance in Wales while conceding that his players needed to be more clinical in taking the opportunities presented to them.
"We'll have to be up in their faces, not giving them room to escape, because like broken field, single mistakes in that collective pressure will open up the field to them," added the 49-year-old.
"They have some fantastic, big, strong, tackle-breaking backs and obviously forwards who can handle them and play ball.
"On the attack side of things, we have to bring tempo to the game, we'll have to move the ball and we have to be brave in the way that we play. Simple, slow ball is not going to cut it against these guys.
"They're a fantastic tackling team so we'll have to move the ball and make it difficult for them to target us.
"And we have to take our opportunities, which is probably the only thing we didn't do against Ospreys. I thought we played really well but finishing off the opportunities that we had was the thing we didn't do.
"This weekend, I don't envisage us having 25 minutes of possession against Clermont, so the possession we do have, we have to make sure we use it properly."
Clermont opener a challenge
Ulster's trip to Clermont is followed by a home contest with Northampton at Kingspan Stadium on 17 December.
This year's European Champions Cup has retained last season's Covid-affected competition's format with the 24 teams divided into two pools of 12.
The eight highest-ranked clubs from each pool will qualify for the knockout stages, with the last-16 taking place over two legs and the final being held in Marseille on 28 May.
Ulster's most recent encounters with Top 14 side Clermont - who are led by Jono Gibbes, McFarland's predecessor at Ulster - saw them earn a home win apiece during the 2019-20 campaign as both teams progressed to the quarter-finals.
"I can't over-emphasise the quality of the challenge that they propose," McFarland said of Clermont.
"In the last couple of weeks, they've been able to bring back in some of their star backs in Alivereti Raka, Damian Penaud and Camille Lopez, so we know the challenge that we've got and we're really looking forward to it."