As reported in the Seattle PI:

Mariners Notebook: Sexson in serious funkHitting just .216, cleanup man tries to retool swing
By JOHN HICKEYP-I REPORTER
MINNEAPOLIS -- Maybe it's a weird time for a makeover, but Richie Sexson doesn't think so.
Sexson is in such a funk with his swing that he's perfectly content to put his old swing behind him and work on a new, improved version.
"The truth is that this is the worst I've ever felt at the plate for this long a period of time," Sexson said before Tuesday's game against the Twins. Five weeks into the season, he came into Tuesday with a .214 average, three homers and 16 RBIs. He went 1-for-4 Tuesday, raising his average to .216.
The average and home run numbers are clearly unacceptable for what Sexson expects from himself. The RBI total isn't bad, save for the fact that 13 of those came by April 15, meaning he's driven in just two runs in the past 15 games.
"I can't remember ever having been this uncomfortable," he said.
What to do? Sexson and hitting coach Jeff Pentland are retooling his swing. There are no illusions it will be a quick process. Sure, there will be occasional explosions like Sexson's 1,000th career hit Monday, a homer. But to remodel a swing isn't the work of a day or even a month.
"If not now, then when?" Sexson said. "The time is perfect for a change, I think. I know I can do better than I've been doing. Right now my swing is in a bad place."
Like most coaches, Pentland waited for Sexson to come to him, knowing that a veteran has got to want to make a change. A coach can make modifications with younger players, as Pentland has done with Jose Lopez and Yuniesky Betancourt, but veterans have their own ideas.