Cape Town - NWU-Pukke wing Joe Seerane and flank Siya Mdaka joined the Springbok Sevens training squad in Stellenbosch on Tuesday as the Blitzbokke try to plug the gaps left by an assortment of injuries to several regulars.Seerane and Mdaka stayed behind in the Cape to train with the national squad after helping the Northwest University side to an exciting 29-all draw against UCT in the Varsity Cup on Monday.Treu had hoped for Shimlas’ SA Under-20 scrumhalf Kevin Luiters to rejoin his squad, but the livewire scrumhalf damaged his knee in Monday’s Varsity Cup action against Tukkies. He enjoyed his first training stint with the Blitzbokke last week.The Springbok Sevens suffered several injury blows while playing in Wellington and Las Vegas last month. Mark Richards was ruled out for up to two months after surgery to repair a torn shoulder muscle. Chris Dry will most likely also not travel to the Far East because of a knee injury, while there are also doubts over the fitness of Kyle Brown (knee) and Boom Prinsloo (neck).The Blitzbokke are currently third in the HSBC Sevens World Series, 16 points behind leaders New Zealand. The Hong Kong tournament takes place from March 23-25 and the Japan event from March 31 to April 1. South Africa will face matches with Wales, USA and New Zealand in Pool B in round six of the World Series in Hong Kong. Pieter Engelbrecht came through unscathed over the weekend while playing for the SA Sevens Academy outfit in Harare where the South Africans finished third overall after losing to hosts Zimbabwe in the Cup semi-final. The Zimbabweans fielded their full World Series squad in preparation for Hong Kong and Japan.William Small-Smith, who rejoined the SA training squad last week after spending some time with the SA Under-20’s, gained valuable playing time in Harare, as did Renfred Dazel, MJ Mentz and Chase Minnaar.Treu is expected to name his 14-man squad on Monday.