"Bruce asked if there was any interest. It fits nicely for us in all three formats. We just need a bit of experience going in support of our young seamers.
"The fact he asked for an early release from his contract just emphasises his desire to play here in New Zealand."
Somerville also received endorsements from former New Zealand batting coach, and New South Wales stalwart, Mark O'Neill, Brisbane Heat and Australian blockbusting top order batsman Chris Lynn and former New Zealand captain Dan Vettori.
"I was very excited about the possibility of coming back to New Zealand," Somerville said.
His chances at NSW have been limited by the presence of Australian international spinners Nathan Lyon and Steve O'Keefe.
"I know Auckland has a talented young group of players and that's an exciting thing to be a part of."
Contract announcements are done in two stages, with the last few places to be revealed on June 30.
The delay is to allow associations to take a breath, check who have been contracted elsewhere and consider their options to complete the group of 16.
Of the six major associations, Auckland have the most places, four, left to fill. Canterbury and Otago need another two players, CD, Wellington and ND have one space remaining.
O'Donnell suggested another fast bowler and a backup batsman are two positions he's looking to fill.
In other developments:
• Northern Districts veteran seamer Brent Arnel has stepped away from the game, after a career which began in 2005-06, having taking 394 wickets in 111 matches at 26.8.
• Central Districts have farewelled Jesse Ryder as they turn their sights on younger prospects, and give first contracts to Willem Ludick and Christian Leopard, both national age group representatives.
• Canterbury has signed experienced Wellington batsman Stephen Murdoch and given first time contracts to three young bowlers, spinners Theo van Woerkom and Blake Coburn, and seamer Andrew Hazeldine.
• Wellington has signed national under 19 allrounder Rachin Ravindra and fast bowler Ben Sears, who is at Lord's on an MCC young player deal.
• Otago have lost experienced wicketkeeper Derek de Boorder, who has moved to Wellington, while fast bowler Neil Wagner has moved to ND and Neesham to Wellington. Their one new face from last season is former CD player Mitch Renwick and there remains a senior quartet of Hamish Rutherford, Mark Craig, Anaru Kitchen and Brad Wilson.