Sept. 14: The Athletics announced that they’ve signed Lamb to a Major League contract after he’d become a free agent (i.e. cleared release waivers). Lefty A.J. Puk, who is slated to undergo shoulder surgery, was moved to the 45-day injured list to open a roster spot. Oakland also placed Frankie Montas on the paternity list and added righty James Kaprielian as the 29th man for today’s doubleheader.

Sept. 13: The A’s are set to sign corner infielder Jake Lamb, as first reported last night by Shayna Rubin of the San Jose Mercury News (Twitter link). The Diamondbacks designated Lamb for assignment on Thursday.

The left-handed hitter isn’t officially eligible to sign until Monday, Rubin adds; presumably, he’s still on release waivers, although it’s a lock he’ll clear them since any team that claims him would absorb what remains of Lamb’s prorated $5.515MM contract. By waiting until he clears waivers, the A’s will leave the Arizona organization on the hook for all but the prorated portion of the league minimum salary. As Susan Slusser of the San Francisco Chronicle points out (on Twitter), Lamb’s deal should be finalized before Tuesday’s deadline for players to be eligible for a new team’s playoff roster.

Lamb came up as a third baseman, but he saw an increasing amount of time at first base in his final couple seasons in the desert. The A’s have Matt Olson locked in at first, so Lamb’s path to playing time in Oakland is surely back at the hot corner. The A’s just found out yesterday that star third baseman Matt Chapman was lost for the season. With Chapman out, Rule V pick Vimael Machin and veteran utilityman Chad Pinder have taken most of the third base work over the past week. Neither Machin nor Pinder has hit well this season, though, so the A’s are adding another bat to the mix. Additionally, Pinder also seems ticketed for the injured list after getting scratched from yesterday’s lineup with a hamstring strain.

Of course, that Lamb was designated for assignment this week speaks to his own recent struggles. While he once looked like a building block for the Arizona organization, the 29-year-old has never returned to form after a 2018 shoulder injury that eventually required surgery. Over the past three seasons, Lamb has combined for a paltry .199/.307/.330 line (73 wRC+) in 514 plate appearances. He’s continued to draw his fair share of walks, but the power he showed from 2016-17, when he combined for 59 home runs, has evaporated. Lamb has just 12 long balls over the past three seasons. He was off to the worst start of his career before the Diamondbacks moved on, hitting .116/.240/.140 in 50 plate appearances.

Lamb will be a free agent at season’s end, so he’s a short-term stopgap for the A’s. Oakland has a 40-man roster spot available already, and further space can be cleared by placing Chapman on the 45-day injured list.