Former All-Star 3B Lamb reportedly joining the A’s

Sometime today, while Matt Chapman is undergoing season-ending hip surgery, the A’s expect to sign a former All-Star to help fill the void at third base.

Jake Lamb, an All-Star in 2017 when he hit 30 home runs for the Arizona Diamondbacks, has an agreement with the A’s, according to multiple sources close to the situation.

Lamb, 29, who was designated for assignment by the Diamondbacks last week, is not eligible to sign a contract until Monday. He will be eligible for the postseason.

His availability should come as no mystery. In 18 games with the Diamondbacks this season, he had five hits (for a .120 average) 17 strikeouts in 43 at-bats and zero home runs.

Lamb’s All-Star season, which included 105 RBIs and was preceded by a 29-homer season in 2016, seems more distant the time passed. Over the past three years, plagued by injuries and inconsistency, he has hit just 12 homers.

With Chad Pinder (hamstring) joining Chapman on the injured list Sunday, the A’s options at third base were Vimael Machín and Tommy La Stella. PATERNITY PAUSE >> Frankie Montas is headed home to the Phoenix area for the impending birth of his daughter and plans to rejoin the team in time for his next start late in the week. LEFTIES GO TODAY >> LHPs Jesús Luzardo (2-2, 3.97 ERA) and Mike Minor (0-5, 6.35) are the probable starters for the doubleheader in Seattle. Minor has allowed six runs in 4 1/3 innings in two appearances.