The Sharks are in line to fill the Bulls' slot as the British and Irish Lions opponents at Loftus this Saturday.
Strong suggestions from people working behind the scenes inside the provincial franchise as well as SA Rugby have pointed to the Sharks filling in the void left by the Bulls, who suffered a Covid outbreak earlier this week.
It will be the second time that the Sharks face the Lions after the tourists defeated Sean Everitt's men 54-7 at Ellis Park on Wednesday.
The Bulls are still hoping to have their postponed tour fixture rescheduled to later in the tour but before the first Test in Cape Town against the Springboks on 24 July.
The Sharks game was in peril, too, after a Lions management staff member tested positive, which forced a number of the staffer's close contacts, including players, into self-isolation.
Wednesday's game received the green light just two hours before the 20:00 kick-off time.
An SA Rugby statement is expected shortly, but Lions managing director Ben Calveley said they were working closely with their South African counterparts to find opponents for Saturday.
"We calmly work through the challenges as they present themselves," Calveley told Sky Sports.
"We take things one step at a time. The focus [on Wednesday] was on getting that fixture over the line, which we did.
"We have turned our attention to the weekend. We know that the Bulls aren't able to put a side out, so we're working with the South African Rugby Union to see if we can find alternative opponents for Saturday.
"If we can't, we'll try to rearrange that fixture for later in the tour. The approach is to just stay calm and focused."
A high-ranking SA Rugby official also told Sport24: "All these things are possible. Those are all suggestions that are being thrown around. It's not firm yet because the Lions have to check their medical team to see if they have fit enough players and get advice from high-performance people."
The Sharks were meant to play Johannesburg's Lions in a Currie Cup game on Saturday at 14:30 but that will no longer be the case.
The Joburg Lions also postponed their pre-match team announcement on Thursday and referred all queries to SA Rugby.