Sharks coach John Plumtree will delay, as long as possible, the announcement of his team to face the Cheetahs in the Currie Cup semifinal in Durban on Saturday.

Plumtree, addressing the media in the build-up to Saturday's big showdown, confirmed that the Springbok and Sharks front row duo of Tendai Mtawarira and Bismarck du Plessis remained on the "doubtful" list - following injuries they sustained in the 45-30 win over Griquas last week.

"Bismarck [du Plessis] and Beast [Mtawarira] are still under a bit of an injury cloud," Plumtree said.

"There will be a bit of light work for them and they have the day off today [Wednesday], so hopefully on Thursday they'll be a lot better.

"It's a big game and both are desperate to play, but we'll pick them only if they're fit."

The Sharks may also be able to bring in the services of lock Johann Muller who has missed the last six matches and 11 in total during the Currie Cup campaign, after fracturing his arm in the first match against Western Province.

"Johann trained hard and there appear to be no repercussions, so it looks like his arm will make it, but he's pulled out late before, so we're just hoping he will be OK," said The Sharks Coach.

Jacques Botes and Deon Carstens will also face fitness testing on Thursday to see if they are ready to play.

With the knock-out nature of semifinals, Plumtree has laid down the law.

"No excuses, it's do or die time," he explained.

"We've had a nice campaign and everyone has performed well and the youngsters have grown, but the responsibility shifts to the players coming back as well as the senior players; it's going to be a big game."

The Free State Cheetahs have won eight of their last 10 matches and carry good momentum into this big match. Having started the tournament poorly, losing their first four matches before kicking into gear, they have been in impressive form and will bring a lot of confidence into this match.

The fact that they have been very competitive against The Sharks in the past may boost their confidence, although that may be tempered by the fact that The Sharks beat them home and away this season, which all counts for nothing given the nature of this match, says Plumtree.

"What's in the past is in the past, this is knock-out time. It doesn't matter how we or they did last week, this is new game. We have plenty of respect for Free State who will come into this game with lots of confidence and we know how tough this will be, much more so than last year's semi against the Lions."

The coach who also won Currie Cup medals as a player for the province back in the 1990s knows only too well what winning means, what is required and the nature of playing at home for the trophy and has urged fans to come out in numbers to support the team.

"We need some serious support," he said.

"There's a perception that we will be in a final, but you can't pick the winners of this weekend's games, they're going to be tight - they have been all year and will finish like that. But to give the team some serious support is great, otherwise there is no advantage having a home game!"