Johnson was signed by the Cardinals off Cincinnati's practice squad Monday, Adam Schefter of ESPN reports.
Johnson will head to Arizona to join his 15th NFL team in 14 NFL seasons. The quarterback is likely poised to operate as the team's primary backup option behind rookie Carson Beck as Beck replaces Gardner Minshew (elbow) as the team's starting QB in Week 10 against the Rams. Minshew is expected to miss the remainder of the 2026 campaign while recovering from a torn UCL, so Johnson will likely stick around Arizona until the season's conclusion.