The Oakland Athletics have officially begun the “buying” process prior to the July 31 trade deadline, acquiring Kansas City Royals reliever Jake Diekman on Friday.

According to Susan Slusser of the San Francisco Chronicle, the A's are now looking to make upgrades to the starting rotation:

Diekman won’t join the A’s until Tuesday, but the Oakland front office is continuing to work to improve the team — and, The Chronicle has learned, the A’s have made calls on one of the biggest fish potentially available, Mets starter Noah Syndergaard, along with another member of New York’s rotation, Zack Wheeler, and Detroit reliever Shane Greene.

Wheeler was a hot commodity on the trade market until he suffered a shoulder impingement that sidelined him for three weeks. However, he returned to throw 5 1/3 innings against the Pirates on Friday, giving up six hits and striking out seven.

Syndergaard has become a name of particular interest in the last week, with multiple reporters suggesting the Mets are hoping to move him before the deadline. The 26-year-old is having the worst year of his career, but he has electric stuff and still has multiple years of control before he becomes an unrestricted free agent in 2022.

The Athletics were never projected to have the strongest starting rotation in the American League, but that unit took a massive hit when Frankie Montas was suspended for a positive PED test.

Oakland has multiple top prospects to dangle in an effort to acquire either Wheeler or Syndergaard — including A.J. Puk and Jesus Luzardo — and general manager Billy Beane has never shied away from getting aggressive for starting pitching, as he was when he acquired the likes of Jon Lester and Jeff Samardzija.