Johannesburg - The Vodacom Bulls and the Sharks both need to win at the weekend to keep themselves in the top four of the Vodacom Super 14 and on course for a place in the semi-finals.With just three rounds left to play, the slightest slip by both teams could prove fatal with at least six teams outside of the top four still in contention for playoff places. The clash between the second-placed Bulls and the Western Force at Loftus Versfeld in Pretoria at 17h05 on Saturday is crucial to the ambitions of both teams. The Force are currently in sixth place, six points off leaders the Hurricanes. A win for the Bulls will virtually end the Force’s hopes of making the playoffs. The last time these sides played at Loftus, the Force won 30-27.The Sharks, meanwhile, are at home to the Highlanders at the Absa Stadium at 15h00 on Saturday. They are in fourth place after their bye last week and will be determined to move up the rankings as they bid for a home semi-final. They have been the pace-setters for much of the competition and should be refreshed after their week off. They face a Highlanders team that have one last chance to keep its playoff hopes alive and will be no pushovers despite a topsy-turvy campaign. The Highlanders were victorious during their last visit to Durban in 2007 and the Sharks will have to take control of the game early on if they are to defeat the Otago franchise on Saturday.Both the Bulls and the Sharks will be hoping that the Vodacom Stormers can cause an upset when they face the Chiefs at Newlands on Saturday at 19h10. The Chiefs, who are in third position on the Super 14 log, third in the table, will be looking to bounce back to winning ways after their defeat to the Bulls last week. They face a struggling Stormers outfit that will be desperate to end their 2009 campaign off on a high note in front of their home fans. The Stormers only won one out of the five away fixtures in Australasia but should be motivated for their first home game in seven weeks.The Bulls and Sharks will be keeping a close eye on the clash between leaders the Hurricanes and the fifth-placed Blues in Wellington on Friday (09h35 SA time). A win for the Auckland outfit will put the skids on the ‘Canes and keep the Aucklanders in the hunt. If the Hurricanes win, they could extend their lead in pole position on the Super 14 log to add further pressure on the chasing pack. The log-leaders will fancy their chances at home as they seem to have hit form at the right time and are playing some great rugby. The Blues have lacked consistency and will be hard pressed to get a result.The Auto & General Lions and the Vodacom Cheetahs – could have an impact on the fortunes of two of the other contenders if they are successful in their matches on Friday. The Lions return to Coca-Cola Park to face the Crusaders at 15h00 whilst the Cheetahs are at home against the Waratahs at 17h05. The Crusaders, who will be without inspirational skipper Richie McCaw, who has been ruled out of the match due to concussion, need to win to remain in the playoff race. They will be looking to bounce back after going down to the Cheetahs last week but could face a Lions team that is determined to get a result in front of their home fans. The Lions have struggled this season despite playing good rugby at times and may fancy their chances against a wounded opponent.The Cheetahs have two wins from three since returning home and will be eager to keep their good form going against the Waratahs. The Australians had a bye last week, which saw them drop to seventh place. The visitors need to win to stay in contention which could play into the Cheetahs’ hands, especially if they can contain their opponents and get an early score. If they can force the Waratahs to chase the game it could open up for them and result in another upset.And finally, the Australian derby between the Reds and the Brumbies takes place in Brisbane at 11h40 (SA time) on Saturday. The Reds, who ended their losing streak against the Blues last week, will be looking to avoid an Aussie whitewash after losing to both the Waratahs and the Force in earlier rounds. The Brumbies, meanwhile, still have an outside chance of reaching the playoffs but must pick themselves up after last week’s eight-try thrashing by the Hurricanes.