Allen was waived by the Commanders on Tuesday, Nicki Jhabvala of The Washington Post reports.
Allen joined the team as an undrafted free agent out of UCLA in May. After missing OTAs later that month due to a hamstring issue, he was able to take the field for training camp to attempt to earn a roster spot. Ultimately, the 23-year-old was unable to do so and will now have to hope for a spot on the practice squad.