The trade became more urgent for San Diego after utilityman Edgar Gonzalez was hit in the head with a pitch on Saturday night and remained hospitalized Sunday.
San Diego is expected to place Gonzalez on the DL. The brother of All-Star first baseman Adrian Gonzalez, Edgar was still complaining of dizziness, ringing in his ears and a partial loss of hearing a day after the frightening beaning.
Gonzalez was hit near the left ear hole on his batting helmet by a 93 mph fastball from Colorado's Jason Hammel.
The Padres were already without starting second baseman David Eckstein, who is on the 15-day disabled list with a strained right hamstring. Eckstein is eligible to come off the DL on Tuesday, but manager Bud Black said that the club is unsure if Eckstein will be ready to return then.
Meredith was 4-2 with a 4.17 ERA in 35 appearances this season. In recent weeks, right-hander Edwin Mujica and rookie lefty Luke Gregerson have supplanted Meredith as the setup man to closer Heath Bell.
Salazar played in 17 games this season for the Orioles, hitting .419 with two homers and six RBIs in 31 at-bats.