Alonso announced his decision to retire Saturday, Brooke Kirchhofer of WWL-TV reports.
Alonso signed with the Saints on Friday, but he second-guessed his decision just a day later. The 31-year-old linebacker hadn't played in the league since 2019, and he wraps up his career having suited up for five NFL teams. In six seasons (86 games), Alonso recorded 588 tackles, three sacks, 10 interceptions, 18 passes defensed, seven forced fumbles and seven fumble recoveries.