The suspension means Blechen, an honorable mention All-Pac 12 player as a sophomore, must sit out the Aug. 30 opener against Northern Colorado as well as the Sept. 7 game at Utah State and the Sept. 15 game against BYU.
Blechen was slated to start at strong safety ahead of junior Quade Chappuis, a former walk-on from Lone Peak High School who played in every game last year and started once at free safety against Washington.
With Blechen out, Chappuis becomes Utah's most experienced player at safety.
Free safeties Eric Rowe, Tyron Morris-Edwards and Terrell Reese are all sophomores.
The Utes open camp Thursday.
While expected to start at safety, Blechen also plays at linebacker, another area in which the Utes are young and have limited experience.
Blechen played the first four games of the 2011 season at linebacker then moved back to safety for the remainder of the season.
He finished the 2011 season with three interceptions and three forced fumbles. He was also third on the team with 78 tackles.
After signing with the Utes as a quarterback, Blechen was moved to safety and quickly developed into one of Utah's best players.
He had four interceptions as a freshman, two of which came at critical times for the Utes.
In his first college game, he intercepted a pass on the first play of overtime against Pitt to set up the winning field goal, and against San Diego State he made an interception in the end zone with 1:22 remaining to preserve Utah's win.
Whittingham was not available for comment on Blechen's status.