Tony Romo's back injury isn't that devastating to the Cowboys, so says Dak Prescott's former coach.

Romo is unlikely to be ready for Week 1 against the rival Giants, thrusting the expected No. 2 quarterback to take over starting the role for the incumbent.

Rodney Guin, who was Prescott's coach at Haughton High in Louisiana, is confident his former player can fill the void successfully.

“Dak always prided himself in being ready to play," Guin told TMZ Sports of Prescott. "He was the most prepared guy on the team ... he was a leader in practice, he earned the respect of all the older players and I can see him doing that on a professional level."

Prescott has looked strong in the preseason thus far. In a 27-17 preseason Week 3 loss to the Seahawks last week, he went 17-for-23 passing for 116 yards with a touchdown and no interceptions.

“I’m not really surprised by his great start," Guin said. "I always knew he would be successful, but it is impressive to see him play so well so early.”

Dallas drafted Prescott, 23, with the 135th overall pick in this year's NFL Draft in the fourth round out of Mississippi State.

Cowboys owner Jerry Jones recently revealed he was so confident in Prescott that he no longer wanted to address his admiration for Johnny Manziel.

If Prescott starts against the Giants on Sept. 11, he'll make his professional debut under the bright lights of "Sunday Night Football."

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