De Vries pitched for Triple-A Rochester on Monday, allowing two runs on six hits over eight innings against Charlotte.
Under the new Collective Bargaining Agreement, the Twins can call up De Vries on Saturday without making a corresponding roster move because rosters are expanded to 26 players for doubleheaders.
"We'll let you know here," Twins manager Ron Gardenhire said. "He's lined up really well here. So we'll see. But we really like to tell the player before we tell [the media]."
De Vries, 27, made three starts with the Twins this season -- going 1-1 with a 4.20 ERA -- before being optioned back Triple-A on June 7.