Stewart (knee) ran the bases on Wednesday and will increase his baseball activities this weekend, Bill Brink of the Pittsburgh Post-Gazette reports.
There is still no timetable for Stewart's return to Pittsburgh. In his absence, Eric Fryer has been serving as the backup catcher for the Pirates. With Fryer playing well, it's unclear whether Stewart will reclaim his spot in Pittsburgh upon his return from the disabled list.
Contreras is out of the lineup Wednesday against the White Sox.
This will be the second day in a row that Contreras is absent from the starting lineup. Miguel Montero will be behind the plate Wednesday, batting fifth.
Grandal is not in Wednesday's lineup against Tampa Bay, J.P. Hoornstra of the Southern California News Group reports.
Grandal is just getting a normal day off, despite his recent power surge. A.J. Ellis will take over behind the plate and will bat eighth.
Ramos went 2-for-4 with a double, two runs scored and an RBI as the cleanup hitter in Tuesday's loss to the Indians.
His stay in the No. 4 spot in the order may not last long, as Bryce Harper was shifted up to the two-hole and went 0-for-5, but Ramos has been productive all season no matter where he's been hitting. The catcher now sports a .339/.390/.546 slash line on the year with 15 home runs and 54 RBI.
Posey went 2-for-4 with a walk, a steal and two runs scored Tuesday against the Reds.
Posey doubled his previous career high with his sixth steal, and padded his OBP by reaching base three times in five appearances. The catcher's .289/.362/.465 line is only inferior to last season's .318/.379/.470 showing due to a slight dip in BABIP from .320 to .297.
Grandal went 1-for-3 with his 14th home run of the season Tuesday against the Rays.
That's eight homers in the past month for Grandal, who is just two shy of last season's career-high total. The recent power surge has raised the catcher's slugging percentage to .430, but a dismal .227 BABIP has suppressed his average to a meager .211 mark.
Molina caught game 1 of the doubleheader, and will get the second contest off as Alberto Rosario gets the nod behind the plate. He went 2-for-4 with a double in the first game Tuesday, to improve his batting average to .283 on the season, while adding on three home runs and 29 RBI.
Rivera went 1-for-2 with a two-run homer and a walk Tuesday against the Cardinals.
Rivera left the yard for the fourth time this year in the fourth inning to pull the Mets within one run in a losing effort. The part-time backstop has homered in two of his seven starts this month, and he's now slugging .356 in 92 at-bats on the season.
Barnhart should be back in the lineup on Wednesday when the Reds take on left-hander Madison Bumgarner and the Giants. The 25-year-old has continued to get better each month, hitting a very respectable .308 in 52 July at-bats. Ramon Cabrera will get the start behind the plate for the Reds on Tuesday.