Smolinski, claimed off waivers from Texas on June 21, was on the bench against the New York Yankees waiting to make his Oakland debut. Manager Bob Melvin said Smolinski will play mostly against left-handed pitching, a problem area for the A's.
Oakland is 5-16 against left-handed starters, the second-worst mark in the majors. The Athletics began the day hitting .238 with 15 home runs vs. southpaws, compared to .267 with 55 homers off right-handers.
Smolinski batted .133 with a homer and six RBI in 60 at-bats for the Rangers this year, but was hitting .427 with six home runs and 23 RBI over 25 games in the Pacific Coast League.
He made his major league debut with Texas last season, batting .349 with three homers and 12 RBI in 24 games. He made an impression on Melvin, too, by doing damage against the A's late in the year.
Bassitt started twice recently and pitched well in place of ailing ace Sonny Gray, hospitalized for a couple of days due to gastroenteritis caused by salmonella.
Bassitt is 0-2 with a 2.95 ERA in seven outings for Oakland this season, five in relief.