The 31-year-old tight end caught 34 passes for 439 yards and five touchdowns last year in Chicago.
Miller was a sixth-round pick in 2009 by the Jacksonville Jaguars and caught 45 passes in three years for the franchise. Injuries derailed Miller's progress, however, and he was out of the game for three seasons.
The Bears signed him in 2015, and he made his biggest contributions in Chicago's second half of the season. All five of his touchdowns came in the final eight games, and his breakout performance came in Week 9 against the Los Angeles Rams, then of St. Louis, catching five passes for 107 yards and two touchdowns.
"I've always enjoyed going to Zach," said Bears quarterback Jay Cutler last season, per Larry Mayer of the Bears' official website. "He's one of those easy guys where you always know where he's going to be and he's a friendly target and he's a smart player. He used to be a quarterback, so he knows tempo things, knows when to gas it a little bit. I've never really second-guessed throwing him the ball."
The Bears placed starting tight end Martellus Bennett on injured reserve last season because of a rib injury, which slid Miller over to the top spot on the depth chart. Chicago didn't miss a beat with Miller, as his speed and athleticism resembled Bennett. He put his athleticism on display in a Monday night game against the San Diego Chargers in Week 8 when he made a game-winning one-handed touchdown grab.
ESPN's Adam Schefter reported March 4 that the Bears were looking to move Bennett. Should the Bears find a new home for Bennett, they at least have an insurance policy in Miller who should receive more opportunities on the field next season.