It's official: Obafemi Martins will be plying his trade in the Chinese Super League this year.

The Seattle Sounders announced on Thursday the transfer of the Nigerian international to Shanghai Greenland Shenhua for an undisclosed sum.

Martins played three seasons with the Sounders, joining as a Designated Player in March 2013 and scoring 40 goals in 72 league appearances.

"We wish Obafemi success on his next challenge. Ultimately this transaction gives us roster and salary cap flexibility heading into our 2016 MLS season, including the opening of a Designated Player position," said Sounders FC General Manager & President of Soccer Garth Lagerwey, in a team statement. "We have a talented and capable group in our locker room, and we're excited for the year ahead."

Martins was spotted at Shanghai Shenhua's training camp last week in South Korea, and wrote a goodbye note to Sounders fans on his Twitter account.

Seattle's MLS season begins March 6, but the club opened competitive play with a CONCACAF Champions League game on Tuesday at home against Club America. They tied the defending champions, 2-2.