"He's a little better, but not ready to go," McClendon said. "If he tells me tomorrow that he's feeling great, then I'll play him. But he's got to be feeling great. That just makes sense."
Jackson, who is batting .252 in 63 games, tested his back in pregame work on Friday and said he's improved considerably in the last two days.
"Really, when it happened it was just hurting to make any type of movements, bending over to put my shoes on, anything like that it would spasm a little," he said. "But now we've got that out of there a little bit, so it's just testing it out swinging it and stuff."
• Veteran right-hander Mark Lowe's 0.67 ERA in his first 27 outings headed into Friday ranked third among all MLB relievers with at least 20 appearances behind Wade Davis of the Royals (0.24) and J.P. Howell of the Dodgers (0.36).
"I'm not sure where we'd be without him," McClendon said.
• McClendon said veteran lefty J.A. Happ will likely pitch a game for Class A Advanced Bakersfield during the All-Star break, then be recalled and slotted back into the rotation in the fourth spot. That would line him up to face the Tigers in Detroit on July 20.
McClendon isn't ready to announce his rotation for the three-game series against the Yankees in New York coming out of the break, next Friday through Sunday, but said he didn't think Felix Hernandez's situation would be impacted if he throws an inning in Tuesday's All-Star Game.
• With his seven shutout innings in Thursday's 7-2 win, Hernandez has now made eight straight starts against the Angels without allowing more than one run. Since 1900, only two other MLB pitchers have given up no more than one run in eight consecutive starts against the same team -- the Giants' Juan Marichal vs. the Mets, from 1964-66, and the Reds' Jose Rijo vs. the Astros from 1988-90.
• Mariners fan Evelyn Jones, who turns 108 on Saturday, is set to become the oldest person to throw out the first pitch at a Major League game when the resident of Woodinville, Wash., makes the ceremonial first toss on her birthday before the 7:10 p.m. PT game against the Angels.
Megan Rapinoe, a forward on the U.S. women's World Cup champion soccer team and member of Seattle Reign FC, will throw out the first pitch prior to Sunday's 1:10 p.m. PT game.