Northampton have bolstered their back-row options with the signing of former London Irish flanker Jon Fisher.
Exeter Chiefs coach Rob Baxter has revealed scrum-half Pat Phibbs is back with the club on a trial basis.
Munster have signed Argentina hooker Eusebio Guinazu on a four-month deal.
Saracens have confirmed the signing of US Eagles international Phil Thiel on a short-term deal.
Johnny Sexton faces a race against time to be fit for Ireland's autumn international Test series after breaking his jaw playing for Racing Metro.
Wasps have admitted they are working hard behind the scenes to find a new ground but are remaining tight-lipped on speculation about where it may be.
O'Connor, 24, is returning to Australia after a spell in Europe, where he featured for London Irish and European champions Toulon.
Richard Hibbard feels his move to Gloucester will give a chance to test himself in the best league in the world.
South Africa have called Warren Whiteley into their squad for the upcoming Rugby Championship Tests in Australia and New Zealand after fellow loose forward Willem Alberts was ruled out through injury.
Northampton director of rugby Jim Mallinder is confident Saints are well equipped for their Aviva Premiership title defence despite their lack of new signings over the summer.
The International Rugby Board will be renamed 'World Rugby' from November 19 in a move described by chairman Bernard Lapasset as a "mission statement".
England coach Stuart Lancaster will be without key front-row duo Dan Cole and Mako Vunipola for this autumn's QBE Internationals.