'Tahs scrum-half Brendan McKibbin is to depart for the United Kingdom to reinforce the Wallabies squad ahead of this weekend's clash with Wales.
The 27-year-old, who made his Super Rugby debut in 2009 and has appeared at state level for both the Reds and the Waratahs, has been called up to replace the Force half-back Brett Sheehan.
Sheehan had the misfortune to suffer an ankle injury during the first half of Saturday's 22-19 win over Italy and was unable to complete the match.
McKibbin has appeared in Super Rugby on 30 occasions, with half of those appearances being achieved this year during a campaign which also saw him regularly handle the goal-kicking.
The new player is expected to arrive in Cardiff on Tuesday and will become the fourth replacement to have joined the tour, following on from the Rebels trio of Scott Higginbotham, Mitch Inman and Caderyn Neville.
A post-game X-ray later cleared Sheehan of any broken bones, and he has travelled to Wales with the squad today ahead of the James Bevan Trophy Test, but will be unable to play a part in the match.
Sheehan will undergo scans in the coming days in Cardiff to determine both the extent of his injury and the course of rehabilitation required.
Waratahs lock Kane Douglas has re-joined the Wallabies squad in Cardiff after missing the Italian leg of the tour in order to stay near his ill mother in London, while he continued rehabilitation from a knee injury.
Douglas will be assessed by the Wallabies medical staff early in the week to determine his availability for the tour's final game.
His return would further bolster the side's second row resources, which took a hit when Rob Simmons was suspended following the tour opening Test in Paris.
The Wallabies' appeal against the eight-game sentence given to Simmons will take place at Bristol on Tuesday night [UK time].