Wednesday, July 14, 2004 By Len Pasquarelli ESPN.com Cowboys center Gennaro DiNapoli, who was expected to compete for the starting job, will instead have to overcome an injury that could sideline him for the start of training camp and perhaps jeopardize his chances of making the roster. Tests revealed that DiNapoli, a six-year veteran who re-signed with Dallas early in the free agent period, has a stress fracture in his right ankle. The injury likely will keep DiNapoli out for at least the first full week of training camp, which begins July 31 in Oxnard, Calif. DiNapoli, 29, began to experience discomfort in the ankle in early June during minicamp. When the pain continued, further tests were recommended by the Dallas medical staff, and those exams revealed the stress fracture. Typical recovery time for such an injury is about four to six weeks. The injury leaves third-year pro Tyson Walter and second-year veteran Al Johnson to vie for the starting job. All three centers had worked with the first-unit offense during Dallas' offseason sessions. A sixth-round draft choice in 2002, Walter has appeared in 26 games with eight starts in two seasons. The former Ohio State standout didn't log a single start, however, last season. Johnson, a second-round pick from Wisconsin in 2003, had actually won the starting job at the beginning of camp last summer. But he suffered a knee injury early in camp, underwent "microfracture" surgery, and missed his entire rookie season. Cowboys coaches are said to admire Johnson's toughness and he probably is the favorite now going into camp. The roster also includes Matt Lehr, who started all 16 contests at center last year, but the Cowboys prefer he play guard in 2004. Dallas signed DiNapoli late last summer and he appeared as a reserve in seven games before going onto injured reserve with cartilage damage to his knee and a high ankle sprain. DiNapoli became a free agent at year's end, but signed a two-year, $1.55 million contract, which included a signing bonus of $350,000, with the Cowboys this spring. He has played in 39 games, with 27 starts, and the Cowboys re-signed him in large part because he represented an experienced insurance policy at the position.