The Springbok had earlier this week announced his departure from the northern province following a three-year stay, ratcheting up speculation that he would head south at the end of this season.
Botha has signed a two-year deal with Munster, subject to him passing a medical and fitness tests, as well as securing a work permit.
Munster coach Tony McGahan said: “We are delighted that BJ Botha has opted to join Munster. He is a player of the highest calibre who we believe will add significantly to our squad.”
Meanwhile, Munster may enjoy a nine-point advantage in the Magners League and stand an intimidating 49 ahead of bottom side Aironi, but manager Shaun Payne still insists they will treat the Italians with due respect when the sides clash at Stadio Luigi Zaffanella, Viadana tomorrow (1pm Irish time).
Both sides are shorn of many of their international stars and while Munster are clearly more seriously affected, they also have much deeper resources at their disposal. This is best reflected by the strength of a bench that contains fully fit again Alan Quinlan, ruled out by a dislocated elbow since the Connacht game two days after Christmas, Denis Fogarty and Marcus Horan, also back after long term injuries, and Doug Howlett, rested after his two-try performance against Edinburgh last week.
The side is captained by Mick O’Driscoll, with Paul Warwick and Duncan Williams taking over from Ronan O’Gara and Peter Stringer at half-back. Sam Tuitupou returns at first centre alongside Lifeimi Mafi, who was outstanding against Edinburgh, while Simon Zebo gets his big chance on the left wing.
Aironi, still seeking their first win, will be without former French full-back Julien Laharrague, who broke his hand during a training session on Thursday, but are strengthened by the availability of two “permit” players, scrum-half Pietro Travagli, who has nine Italy caps, and hooker Tommas D’Apice.
It will also be a big day for New Zealander Nick Williams, who spent two seasons with Munster without ever quite making the hoped-for breakthrough. He now holds down the number eight position with Aironi and Munster won’t need any reminding of how dangerous he can be from close range.
“We went over to Treviso a couple of weeks ago and came unstuck,” says Shaun Payne.
“Aironi gave a good show against Leinster the last time they played out there and obviously they beat Biarritz at home in the Heineken Cup. I know they haven’t had a win yet in the Magners League, but it’s only a matter of time before that happens. We played them first up at Musgrave Park and they showed just what they are capable of and scored a good try right off the bat.
“Still, I think we’re on an upward curve. We obviously haven’t been playing with a whole heap of confidence but I think we did really well against Edinburgh, and if we carry on the good work at the set piece, I see no reason why we can’t put in a good performance,” he added.
“We are working our asses off week-in, week-out on the set-piece. This is not just hit and hope.”
AIRONI: D Demas; K Robertson, G Pavan, M PrattichettI, G Toniolatti; J Marshall, P Travagli; A Di Marchi, T D’Apice, F Staibano, J Furno, M Bortolami (capt), J Sole, G Krause, N Williams.
Replacements: R Santamaria, L Redolfini, A De Marchi, G Biagi, N Cattina, G Bronzini, R Bocchino, G Pizarro.
MUNSTER: J Murphy; Denis Hurley, L Mafi, S Tuitoupu, S Zebo; P Warwick, D Williams; W Du Preez, D Varley, T Buckley, I Nagle, M O’Driscoll (capt), D Ryan, T O’Donnell, J Coughlan.
Replacements: D Fogarty, M Horan, S Archer, B Holland, A Quinlan, C Murray, D Cusack, D Howlett.
Referee: D Jones (Wales).