CHICAGO — The A’s already needed an additional starter in the coming days, thanks to Friday’s doubleheader. Then Daniel Mengden left his outing against the White Sox after two innings because of a foot injury.

A much-traveled veteran will get the first crack at a spot in Oakland’s rotation: The Chronicle has learned that the pitching-starved A’s will turn to veteran Edwin Jackson for a start at Detroit. Oakland will be Jackson’s 13th major-league team, tying former Oakland reliever Octavio Dotel’s record.

Jackson, a right-hander signed to a minor-league deal June 6, is likely to start Monday at Comerica Park, based on his current schedule. Jackson, 34, had been scheduled to go for Triple-A Nashville that night, but on Saturday the Sounds were listing TBA for Monday.

Over 15 seasons, Jackson is 98-120 with a 4.67 ERA in 377 appearances, including 288 starts. He has not pitched in the big leagues this season, and opted out of his minor-league deal with the Nationals in May after putting up a 3.40 ERA in 10 starts with Syracuse. Jackson is 0-1 with a 4.02 ERA in three starts with Nashville, where he has allowed 12 hits and eight walks in 152/3 innings.

The A’s will have to make a 40-man roster move to add Jackson; Andrew Triggs is a potential candidate for the 60-day disabled list after a small setback in his return from nerve irritation in his right arm. Triggs has not yet made a rehab start, so he remains several weeks away from being an option at the big-league level.

Oakland already has five starters on the DL: Triggs, Brett Anderson, Trevor Cahill, Daniel Gossett and Jharel Cotton; Cotton, like top prospect A.J. Puk, is out for the season after Tommy John surgery.

As a result, the A’s have been trying to add starting pitching depth, and according to sources, they have discussed possible deals with Boston, which is looking for outfield help and which unsuccessfully asked about Mark Canha. There is a chance the teams will revisit things as next month’s trade deadline approaches.

Anderson threw four shutout innings for Nashville on Saturday night and could be an option next week if Mengden were to miss time; Chris Bassitt, demoted Saturday, could be recalled in the event of an injury.

Susan Slusser is a San Francisco Chronicle staff writer.