MacDougal had an out clause in his Minor League contract that allowed him to leave Triple-A Syracuse on Monday night. However, the Nationals had 48 hours to put him on the 25-man roster. If they didn't, MacDougal would have become a free agent.
MacDougal pitched in seven games and gave up one run in 7 1/3 innings for Syracuse.
As for Montz, he was put on the 25-man roster on Wednesday after right-hander Daniel Cabrera was designated for assignment. Montz is the backup catcher for Wednesday's game against the Mets, because catcher Josh Bard is in Colorado because his wife is having a baby.
Entering Wednesday's action, Montz was hitting a combined .158 with two home runs and eight RBIs for Harrisburg and Syracuse.
"[Harrisburg manager] John Stearns called me into his office and he had an itinerary in his hands," Montz said. "I was not expecting to come here. He told me what was going on with Bard. [Stearns] said I was coming up for a day or two because of the off-day. I should be here for the night and go back to Harrisburg. ... Of course, you want to stay in the big leagues. I still have some work to do -- some improvements."
Montz acknowledged that he was upset when he was sent down to Triple-A Syracuse during Spring Training and he let it affect his play during the season.
"I should have been better than that. But I feel great, I have been catching great," Montz said.
In other news, catcher Jesus Flores, on the disabled list because of a right shoulder bruise, is expected to be activated from the disabled list on Friday.
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.