Brink has been sidelined for several weeks with a broken wrist but is expected to come off the bench in the all-important match.
A win for the Lions - which would be their fourth in five matches - will secure them a place in the semi- finals in a few weeks’ time.
And, in further good news for the Joburg team, wing Aphiwe Dyantyi is back training with his Lions team-mates and expected to start taking contact in two weeks’ time.
It is understood that if the Springbok management team require him to play - to prove his fitness - he could do so in three weeks’ time, possibly in the semi- finals.
While Dyantyi’s hopes of being included in the 31-man squad to feature at this year’s World Cup in Japan are probably over, if fit he could still find himself on a standby list should he be needed in case of injury downing someone who will be named in the initial squad on August 26.
Lions coach Cash van Rooyen said the return to the squad of Brink would be a big boost ahead of the visit by the “physical” Sharks.
“Cyle brings a bit of experience, so it’s nice having him back. He’s also got a real physical presence, but at the same time he is a calming figure as well.
“The Sharks are normally a big, physical, team, and they thrive on momentum, so we’re expecting it to be a big physical clash.”
Van Rooyen has, in fact, made a number of changes to the team that lost to the Blue Bulls last week.
Among the backs, a fit-again Manny Rass partners Wandisile Simelane in the centres, while up front, James Venter swaps places with Marnus Schoeman, while in the second row Wilhelm van der Sluys returns after sitting out last week because of concussion.
And in the front row the experienced Frans van Wyk plays instead of the injured Johannes Jonker.
Meanwhile, the Lions have announced that three of their most promising youngsters - Dillon Smit, Pieter Jansen and Hacjivah Dayimani - have extended their contracts with the union.
“When players sign to continue playing here, it’s a positive,” said Van Rooyen.
Tomorrow’s match at Ellis Park kicks off at 2pm.
Starting XV: Tyrone Green, Madosh Tambwe, Wandisile Simelane, Manny Rass, Stean Pienaar, Shaun Reynolds, Ross Cronjé, Hacjivah Dayimani, Len Massyn, James Venter, Wilhelm van der Sluys, Ruben Schoeman, Frans van Wyk, Pieter Jansen, Sti Sithole
Replacements: Jan-Henning Campher, Nathan McBeth, Jacobie Adriaanse, Rhyno Herbst, Cyle Brink, Marnus Schoeman, Dillon Smit, Duncan Matthews