COLUMBIA, Mo. -

Gary Pinkel officially opened his 12th season at Mizzou Thursday with the Tigers first fall practice of 2013.

Mizzou was one of four SEC schools (Georgia, Vanderbilt, Mississippi State) to open camp Aug. 1.  In fact, those were the first four schools in the league to open practice.

Before the practice began, the coach released the names of the four senior captains on his new website, GaryPinkel.com.  QB James Franklin, WR L'Damian Washington, LB Andrew Wilson, and CB E.J. Gaines were bestowed the honor by their teammates.

After the practice, though, Pinkel was adamant that a captaincy does not guarantee a spot in the starting lineup, alluding to the ongoing competition at starting quarterback between Franklin, Maty Mauk, and Corbin Berkstresser.

Once on the Kadlec Practice Fields, the Tigers donned only helmets and shorts. 

Two players were seen wearing red bibs, signifying some kind of injury.  Freshmen DT A.J. Logan (Rock Bridge HS) and CB Anthony Sherrils. 

Logan is dealing with a minor knee injury.  Sherrils, on the other hand, is medically cleared to play but the training staff is being cautious with him after he was involved in a car accident earlier this summer. 

Notable players listed atop the depth chart included Franklin at quarterback, wide receiver Dorial Green-Beckham at the "X" position, and running back Henry Josey.

One player listed on the roster who was not at practice was S Duron Singleton.  A junior college transfer, Pinkel told the media after practice that Singleton would not be playing at Mizzou for "personal reasons."

Less than a week ago, Singleton tweeted the following: "Man words cant even describe how I feel right now.. I put so much into being where I am today and to be here. one word ?#Blessed #SEC #mizzou"

The Tigers resume practice Friday morning at 7:15 a.m.