IRVING — The Dallas Cowboys came to terms with second-round draft pick Gavin Escobar on a four-year deal Friday.The contract is worth roughly $4.3 million for the tight end, who is set to back up Pro Bowler Jason Witten in 2013 and be groomed as his successor at the position. Escobars signing leaves only top pick Travis Frederick without a contract with less than a month before the start of training camp. However, with their other 2103 draft picks in the fold, the Cowboys believe they will soon get a deal with Frederick, who is already penciled in as the starting center.Escobar is expected to play a big role as a rookie. The Cowboys plan to use more two-tight-end sets to get him and Witten on the field together. He could be a huge factor in the red zone.The Cowboys report to training camp on July 19.