Hatcher to join bullpen

Oakland added another contestant to the “Who can pitch the seventh and eighth innings?” competition Tuesday.

The A’s acquired reliever Chris Hatcher from the Dodgers in exchange for $500,000 in international-bonus-slot money, which will allow Los Angeles to spend more for international free agents. Oakland already is working under spending restrictions after surpassing its limit last year, and the team sent $1.5 million in international-bonus-slot money to the Yankees last month in the Sonny Gray deal.

Hatcher is expected to join the A’s on Wednesday, according to sources. The 32-year old completed a rehab assignment Sunday after missing seven weeks with thoracic inflammation. He was 0-1 with a 4.66 ERA in 26 appearances with Los Angeles, and he racked up 43 strikeouts in 362⁄3 innings.

In his seven big-league seasons, Hatcher is 8-14 with a 4.72 ERA in 193 appearances, giving some experience to a bullpen lacking in pitchers with extensive big-league experience apart from Santiago Casilla. And with the A’s bullpen still in flux after Sean Doolittle and Ryan Madson were dealt to Washington last month, the rest of the season will serve as audition time.

“There’s a great opportunity here for relievers, the way things have gone for us,” manager Bob Melvin said. “We’re looking for some guys who can pitch and pitch well for us.”

Oakland’s bullpen entered Tuesday with a 4.60 ERA, second worst in the league, and its 19 blown saves were tied for third most.

Briefly: Reliever Bobby Wahl, who had surgery for thoracic-outlet syndrome Monday in Dallas, probably will be ready for the start of spring training, Melvin said. … Starter Andrew Triggs, who had surgery to repair a torn hip labrum a month ago, is off crutches and his rehab is going well, he said . ... Chris Bassitt, who is off the disabled list and working in relief at Triple-A Nashville, has a 7.45 ERA. “He’s back and forth,” Melvin said. “There are games he’s been effective and games he’s struggled some. I think he’s having trouble finding some consistency after coming back from” Tommy John surgery.

Susan Slusser is a San Francisco Chronicle staff writer.