In the postseason, Brien owns a 70% career field goal percentage on seven-of-10 field goals. With the Jets, Brien converted three-of-six postseason field goal attempts, all taking place after the 2004 regular season, and hit a game winning 28-yard field goal in overtime at San Diego on January 8, 2005 in an AFC Wild Card game.
With the Jets in 2003, Brien's 84.4% conversion percentage on field goals ranked third all-time in Club annals, while his 82.8% in 2004 ranked fifth all-time in the team's record books. The former San Francisco draft choice in 1994 out of Cal-Berkeley kicked as a rookie with the 49ers before hooking on with the New Orleans Saints midway through the 1995 season. He performed for the Saints through the 2000 season, finishing as the second most accurate kicker in Saints' history (82.6%). He ranks second all-time in Saints history in points scored (513) and FGM (123). He kicked for both the Indianapolis Colts and Tampa Bay Buccaneers in 2001 and in 2002 with the Minnesota Vikings before joining the Jets in 2003 as an unrestricted free agent.