The 24-year-old Wheeler split the 2012 season between Arizona and Triple-A Reno. Called up by the D-backs on July 20, he hit .239 in 50 games with one home run and 10 RBIs, playing mostly at third base.
While at Reno, he hit .351 with 15 homers, 90 RBIs and a .960 OPS in only 93 games and was a Triple-A All-Star. He was a fifth-round Draft pick in 2009 out of Loyola Marymount University and was Arizona's Minor League Player of the Year.
Major League Baseball's deadline to protect players is Tuesday at 9:59 p.m. MT. Players first signed at age 18 must be added to 40-man rosters within five years or they become eligible to be drafted by other organizations through the Rule 5 process. Players signed at 19 years old are to be protected within four years.
Clubs pay $50,000 to select a player in the Rule 5 Draft, to be held on Dec. 6 at the conclusion of the Winter Meetings in Nashville, Tenn. If that player doesn't stay on the 25-man roster for the full season, he must be offered back to his former team for $25,000.
Wheeler's younger brother, Jason, was an eighth-round pick of Minnesota in 2011 and was a Class A All-Star in 2011 for Cedar Rapids.
Reynolds, 28, went 3-1 with a 4.40 ERA in 71 appearances for the Rockies in 2012.