Updated

OAKLAND, Calif. (AP) The Oakland Athletics have begun their expected changes leading up to the trade deadline, sending left-hander Scott Kazmir to his hometown Houston Astros for a pair of minor leaguers Thursday.

Oakland receives right-handed pitcher Daniel Mengden and catcher Jacob Nottingham in the swap with its division rival - and the Astros received a top-tier starter as they chase a playoff berth in the season's second half. They haven't been to the playoffs since being swept in the 2005 World Series by the Chicago White Sox when Houston was still in the National League.

Mengden and Nottingham were at Class-A Quad Cities to start the season before being promoted to the organization's higher-A club in Lancaster of the California League.

The A's made the announcement ahead of their afternoon series finale against Toronto, so instead of Kazmir starting against the Blue Jays he was saying his goodbyes in the clubhouse.

Oakland recalled right-hander Arnold Leon from Triple-A Nashville to take Kazmir's roster spot.

Kazmir went 5-5 with a 2.38 ERA in 18 starts for Oakland. The lefty had been considered someone the A's might try to swap before the July 31 deadline. Oakland acquired Kazmir as a free agent in December 2013 and he was 20-14 with a 3.12 ERA in 40 starts over parts of two seasons for the A's.

Houston (53-43) began the day in second place in the AL West, two games behind the defending division champion Los Angeles Angels. The Astros were hosting Boston in a night game Thursday.