Jimenez will start in place of Chris Tillman, who was put on the DL Tuesday. Jimenez has allowed five runs in eight innings out of the 'pen this month after being demoted from the rotation. He gave up one run in five innings in a spot start July 28.
Scherzer is 4-2 with a 3.81 ERA in eight career starts against the Orioles. He is also 9-6 with a 2.75 ERA in Interleague games when pitching at home over the course of his career.
The O's have yet to name a starter, but it could be righty Mike Wright, who's up from Triple-A Norfolk to take the place of ace Chris Tillman, who went on the 15-day disabled list with right shoulder bursitis.
Estrada looks to bounce back after two consecutive rocky outings. Over his last two starts, the finesse right-hander has allowed 11 earned runs, including five home runs, over nine total innings.