The 2013 NFL combine is officially underway today, with Groups 1, 2, and 3 beginning to go through the vetting process after arriving in Indianapolis on Wednesday. Unfortunately, most of what's going to go on on Thursday is behind the scenes stuff, such as medical checks, media interviews, and team interviews.
Related: Complete 2013 NFL combine coverage
According to NFL.com, this is the official schedule for Thursday, February 21st:
Group 1 (PK, ST, OL) Group 2 (OL) Group 3 (TE)
Measurements - Medical Examinations - Media - Interviews
Group 4 (QB, WO) Group 5 (QB, WO) Group 6 (RB)
Travel to Indianapolis - Registration - Hospital Pre-Exam & X-Rays - Orientation - Interviews
The "meat market" portion of the combine will go down for the offensive lineman and tight ends and when the full measurements are available, we will have them for you to go over. One of things you might want to look for on offensive lineman in the measurements is long arms, as this is generally a coveted trait, especially for offensive tackles.