The 26-year-old is expected to become first choice No 10 at the Aviva Premiership club after joining from Highlanders. The transfer spreads further uncertainty over Danny Cipriani.
Arsene Wenger will serve the second of a three-match touchline ban when Arsenal face Chelsea in the first leg of the Carabao Cup semi-final on Wednesday night at Stamford Bridge.
The January transfer window is hotting as Premier League clubs up and down the country bid to strengthen their squads for the second half of the season. Follow all the news with Sportsmail.
So, which other clubs have been involved in the biggest transfer profits? And who tops the list? Here, Sportsmail has compiled a list of some of the biggest mark-ups.
Tosin Adarabioyo, who last year negotiated a £25,000-a-week contract after threatening to leave, is the new owner of a six-bedroom home in Knutsford, Cheshire.