OKLAHOMA CITY - The 2012 NFL Scouting Combine began Thursday at Lucas Oil Stadium in Indianapolis.

More than 300 top prospects for this year's NFL draft were invited to participate in the combine that is full of physical, mental and performance tests.

Coaches, scouts, executives and doctors from all 32 NFL teams will be present to conduct the four-day tests in preparation for this season's draft.

The participants will test their skills in measurable drills that include: bench press, 40-yard dash, vertical jump, broad jump, three cone drill and the shuttle run.

A total of 13 players that spent their college years in Oklahoma will take part in this year's combine.

Seven Sooners and six Cowboys will push their limits in hopes of improving their draft stock.

The more than 300 players were divided by position into nine groups.

The combine got started Thursday with medical exams, measurements, psychological tests, interviews and with the players meeting with the media.

One big development from the opening day of the combine was the announcement that former Alabama running back Trent Richardson underwent a minor knee surgery and will not participate in any on-field drills as he recovers.

Richardson's representatives sent a memo to all 32 NFL teams informing them of the surgery. The memo also stated he is expected to be able to do on-field drills by the end of March.

Richardson will take part in the medical exams over the four-day combine.

Stay tuned throughout the weekend to see how your favorite in-state players performed during the combine.

Oklahoma Combine Participants Include:
-DE, Frank Alexander
-WR, Ryan Broyles
-CB, Jamell Fleming
-OLB, Ronnell Lewis
-OLB, Travis Lewis
-T, Donald Stephenson

Oklahoma State Combine Participants Include:
-WR, Justin Blackmon
-DE, Jamie Blatnick
-WR, Josh Cooper
-FS, Markelle Martin
-FS, Johnny Thomas
-QB, Brandon Weeden