Five of their six coaches have been given contract extensions for 2010, but the Seattle Mariners have the sixth – third base coach Bruce Hines – that he won’t return next season.

Hines, 51, was told last week that he wasn’t being retained, though neither general manager Jack Zduriencik nor manager Don Wakamatsu has yet discussed the firing – or the reasoning behind it.

The team will announce today the extensions of bench coach Ty Van Burkleo, pitching coach Rick Adair, batting coach Alan Cockrell, first base/outfield coach Lee Tinsley and bullpen coach John Wetteland.

Hines, who worked with Mariners infielders in 2009, is the son of former Seattle coach Ben Hines. The team will begin conducting interview to find his successor within the next few days.

The move is something of a surprise – it certainly caught Hines off-guard. A popular coach among the players and staff members, his dismissal will be explained in the days to come.

Stay tuned.