[1] After redshirting his first year at Washington in 2017, Haener appeared in four games as a backup to Jake Browning in 2018, completing 9 of 13 passes for 107 yards with one touchdown and one interception.
[2][3] After sitting out his first year at Fresno State due to transfer rules, Haener became the starter in 2020.
[8] Haener was selected by the New Orleans Saints in the fourth round (127th overall) of the 2023 NFL draft.
He released a statement: "I still do not know how the substance got into my body, as none of my supplements or prescribed medications contain the banned ingredient", nonetheless subsequently stating "I must take full responsibility for the failed test".
In Week 7 against the Denver Broncos, he relieved Spencer Rattler on the final drive of the game, and recorded his first career touchdown on a 12–yard pass to Cedrick Wilson Jr.[13] After Carr suffered a hand fracture in Week 14, the Saints named Haener their starting quarterback.