Tolleson is batting .265 with 11 RBIs in 26 games for Triple-A Norfolk, and manager Buck Showalter said Tolleson has the ability to play second base, third base, shortstop and either corner outfield spot.
"We feel like he serves a need we have," Showalter said. "He's probably swinging the bat as well as anybody they've got down there. I was impressed with him in the spring, and I think as the week develops it'll reveal itself a little bit more to why this is happening in the sequence it's happening."
Tolleson started the Tides' game on Wednesday in Louisville but was pulled after one at-bat to make the trip to Baltimore. Showalter said Tolleson got on a plane around 4 p.m. ET.
With Ryan Flaherty slated to start in left field before Wednesday's rainout, Tolleson gives the Orioles the versatile presence off the bench that Flaherty usually provides.
Because Opening Day starter Nolan Reimold is still on the disabled list and fourth outfielder Endy Chavez is sitting to rest a sore oblique muscle, Flaherty and Tolleson could see increased playing time.
"We have a need for Stevie," Showalter said. "There were some people to pick from, so it wasn't clear cut. But for what our needs are right now we wanted to go with Stevie."
Showalter added that Chavez was available if needed Wednesday, but his status would likely become clearer in the next day or two.
"Last night before the game he said it's the best he's felt," Showalter said. "The last at-bat he felt it a little bit."
Phillips had his contract selected on Tuesday to provide relief for an Orioles bullpen that was still recovering from Sunday's 17-inning game against Boston.
He entered in the seventh inning of Tuesday's 10-3 loss to the Rangers, recording only two outs while giving up two runs on three hits and two walks, including the third of Josh Hamilton's four home runs.