Botha, a former Sharks captain, was one of the stand-out performers for the Sharks on their recent overseas tour.
Botha joins an exodus from Durban that already includes all three Du Preez brothers, Robert, Dan and Jean-Luc (all Sale Sharks), Akker van der Merwe (Sale), Philip van der Walt (Newcastle), Coenie Oosthuizen (Sale) and Jacques Vermeulen (Exeter Chiefs).
Botha will initially join London Irish on a six-month contract, acting as cover during the World Cup. He will then take up a spell with the Kubota Spears in Japan, before joining London Irish in preparation for their 2020-21 campaign.
But that is next year and for now the main thing is that the in-form Botha will be leading the forward charge for the Sharks when they take on the Lions on Saturday at Jonsson Kings park (5pm).
It is an absolute must-win for the Sharks given the congestion in the South African Conference. It is so tight that the Sharks went into their bye weekend on top and by the end of the Stormers game on Saturday night they had dropped to fourth.
After 14 rounds of action, with four remaining and with all five teams having played 12 games, the Bulls and Jaguares have 32 points each from 12 games, with the men from Pretoria on top courtesy of a better points difference. The Lions are third (30 points), followed by the Sharks (29) and Stormers (26).
On Friday, the Bulls are away to the Brumbies in Canberra, and on Saturday the Jaguares play the Waratahs in Sydney. The Stormers host the Highlanders in Cape Town and the Lions visit the Sharks at Jonsson Kings Park in what is shaping up to be a do-or-die battle for both sides.
The Sharks simply have to turn around their poor home form and win this one because their countdown to the play-offs only gets tougher.
Next week the formidable Hurricanes are in town and then the Sharks have a very tough final fortnight with away games against the Jaguares and Stormers.
The Crusaders’ match against the Stormers emphasised how difficult the Capetonians can be at Newlands, and you can bank on the Stormers getting up for a derby with the Sharks in the same fashion they did for the champions last week, especially with it being possibly the last game for their coach, Robbie Fleck.
But before the Newlands finale, the Sharks have a potentially tougher assignment in Buenos Aires against a Jaguares team that is timing its run in the competition perfectly.
The Jaguares’ win over the Hurricanes in Wellington shocked many, but it really shouldn’t have been that much of a surprise given the form of the Argentinians in the past month.
One would have to say that the Jaguares must now be favourites to beat the Waratahs and Reds in Australia, while they then finish the pool stages with home games against the Sharks and Sunwolves.
It certainly looks like the Jaguares are the team to beat in the SA Conference, and if the Sharks want to have the Conference title riding on their game in Buenos Aires in three weeks time, they are going to have to win their home games against the Lions and Hurricanes.@MikeGreenaway67