Ottawa Redblacks Following his time in
Western Canada Arndt signed with the
Ottawa Redblacks on September 13, 2017. Arndt spent the closing three months of the season learning from the sideline. He was re-signed by the team on January 3, 2018. Arndt spent the entire
2018 season in the CFL as a backup quarterback behind
Trevor Harris. For most of the
2019 season Arndt was the third sting quarterback behind
Dominique Davis and
Jonathan Jennings. Arndt came in relief of starting Jennings in the second half of the team's Week 15 loss to the
BC Lions. As the team fell to a record of 3–11 Arndt was named the starting quarterback for the team's Week 18 match against the
Toronto Argonauts. In his first career start Arndt completed 28 of 42 pass attempts for 288 yards with two passing touchdowns and three interceptions. Arndt started the following match against the division leading Ti-Cats but was unable to effectively move the ball down the field, completing 17 of 30 pass attempts for only 112 yards with no touchdowns or interceptions. Arndt made his third and final start of the season in the second last game of the season. He was released by the Redblacks on January 23, 2020.
BC Lions Arndt signed with the
BC Lions on January 30, 2020. However, he did not play in 2020 due to the cancellation of the
2020 CFL season and was then released during 2021 training camp on July 26, 2021.
Albany Firebirds On February 24, 2024, Arndt signed with the
Albany Firebirds of the
Arena Football League (AFL). == Coaching career ==