The Sabres selected Miller during the fifth round of the 1999 NHL Entry Draft. He appeared in a combined 15 games for Buffalo during the 2002-03 and 2003-04 seasons before becoming one of the key figures among a young core that transformed the franchise following the 2004 lockout.
Miller assumed No. 1 duties on teams that went to back-to-back Eastern Conference Finals in 2005-06 and 2006-07, a role he did not relinquish until he was traded to the St. Louis Blues on Feb. 28, 2014. In the intervening years, he became a leader on the Sabres, a decorated Olympian, and a dedicated member of the Western New York community.
Miller's most dominant season came in 2009-10, when he posted a career-high .929 save percentage and a 41-18-8 record to lead the Sabres to a Northeast Division title and capture the Vezina Trophy as the NHL's top goaltender. That same winter, Miller was chosen as Tournament MVP at the 2010 Winter Olympic Games in Vancouver after helping Team USA to a silver medal.
Miller was committed to the Western New York through his Steadfast Foundation and his support of the Courage of Carly Fund at Roswell Park Comprehensive Cancer Center, earning recognition as the 2009-10 recipient of the NHL Foundation Player Award. The goaltender continued to visit Roswell on road trips as a visiting player and last spring dedicated a portion of proceeds from a used equipment auction to FeedMore WNY and the Buffalo Police Athletic League.
Miller played his last game in Buffalo on Feb. 9, 2020 as a member of Anaheim, a 31-save performance in front of a fanbase that remained appreciative more than six years removed from his last game in a Sabres uniform.