Another day, another change in the upcoming starting rotation.

Manager Don Wakamatsu just told me (ok, me and a few others) that right-hander Brandon Morrow will remain in the starting rotation with the Mariners and start Thursday’s series finale against the Padres in San Diego.

Lefty Jarrod Washburn was slated to start that game, but his back gave out on him again yesterday and he has now been pushed back to Friday, or perhaps Saturday. Stay tuned on that one.

Fellow lefty Erik Bedard, who missed one start because of slight inflammation in his left should, was penciled in to start Friday, but now might go on Saturday, depending on Washburn’s health.

What we know for sure is that the rotation against the Padres is: ace right-hander Felix Hernandez pitching the series opener on Tuesday night, followed by left-hander Garrett Olson and Morrow, whose pitch count will be increased to 75 to 80.

Meanwhile, rookie reliever Shawn Kelley threw off a mound for the first time since straining his left oblique on May 5 in Seattle. He threw 25 pitches in the bullpen this morning and was all smiles when it was finished.

He will throw another BP on Tuesday in San Diego.

And today’s Mariners lineup:

1. Ichiro, RF

2. Russell Branyan, 1B

3. Adrian Beltre, 3B

4. Jose Lopez, 2B

5. Ken Griffey Jr., LF

6. Yuniesky Betancourt, SS

7. Guillermo Quiroz, C

8. Franklin Gutierrez, CF

9. Jason Vargas, P

— Jim Street