YOU would think they would have seen this coming.

“The Mentalist” stars Owain Yeoman and Amanda Righetti are getting the ax before the end of the upcoming season, The ENQUIRER has learned…just as their characters are heading toward a wedding!

The actors, who play Special Agents Grace Van Pelt and Wayne Rigsby of the fictional California Bureau of Investigation, have been with the series since the show’s first season.

“Their characters are an on-again, off-again couple who were very definitely back on by the end of last season,” said an insider.

 “As the CBI chases down serial killer Red John in Sea­son 6, they decide to get engaged…and leave the Serious Crimes Unit.”

Meanwhile, the show’s main star – 44 year-old Aussie star Simon Baker who plays “psychic” Patrick Jane – is pulling in a whopping $350,000 per episode after salary negotiations.

Rather than being down about moving on, how­ever, Owain and Amanda are actually looking forward to the downtime, says the source.

“Amanda had a baby boy, Knox, with director hubby Jordan Alan in January,” the source noted. “So now she’ll have more time to spend with her son.”

Owain recently got engaged to girlfriend Gigi Yallouz and just re­turned from a romantic trip to Bali.

“Now, they can devote them­selves to planning their big day,” the source added.