UPDATE (Thursday at 1:45pm) -- The A's officially selected the contract of infielder Matt Chapman from Triple-A, the team announced in a press release.
To clear space on the roster for their highly-touted prospect, the A's designated infielder Trevor Plouffe for assignment.
Plouffe, who signed a one-year free agent deal with the A's this offseason, was hitting .214 with seven home runs in 14 RBI in 58 games. He was 2-for-30 over his last 12 games and is tied for fourth in the American League with 10 double play balls.
An A's season that is sliding downhill quickly will get a boost with news that third baseman Matt Chapman will join the team Thursday.
A source confirmed to NBC Sports California that Chapman, the team's No. 3 prospect as ranked by Baseball America, will receive his first major league call-up and be in Oakland for the start of a four-game series with the New York Yankees.
It's the most dramatic statement yet that Oakland is turning the page and looking toward the future after completing a 1-5 road trip that has dropped its overall record to 27-38, 16 1/2 games out in the American League West.
Chapman's arrival suggests that Trevor Plouffe's time as the everyday third baseman is over. The first-year Athletic, signed to a one-year $5.25 million deal in the offseason, has hit just .215 with seven homers and 14 RBI.
Chapman hit .259 with 16 home runs in just 48 games with Triple-A Nashville, the early part of his season interrupted by a wrist injury. Though he's accumulated a high number of strikeouts as well - 63 in those 48 games - he boasted a .350 on-base percentage that is a marked improvement over the .328 mark he had last season spent mostly with Double-A Midland.
The A's have been conservative to this point with Chapman and their other top hitting prospect at Nashville, middle infielder Franklin Barreto, saying they've wanted each to get more seasoning at Triple-A. They feel the time is now right for the 24-year-old Chapman, their first-round pick in 2014 out of Cal State Fullerton.
He's swatted a combined 59 homers over his past two seasons in the minors and has continued to display the defensive ability at third that team officials believe is Gold Glove-caliber for the future.
In discussing Chapman recently, A's coordinator of instruction Ed Sprague raved about Chapman's abilities with the glove.
"He could (even) be a Gold Glove shortstop, he's that athletic," Sprague said.
The San Francisco Chronicle was first to report news of Chapman getting promoted.