Dallas running back Phillip Tanner was virtually phased out of the Cowboys’ offense in the second half of the 2012 season.The former Dallas Kimball High School standout’s role was reduced, in sharp contrast to his weight. After the Cowboys selected Oklahoma State running back Joseph Randle with their fifth-round pick in April’s draft, there were rumblings that Tanner could be the odd man out on the 53-man roster.Last season, the third-year running back had 25 carries for 61 yards with a long run of 9 yards. He also had four receptions for 41 yards. The backfield is stacked. DeMarco Murray is the starter, with second-year speedster Lance Dunbar, Randle, undrafted rookie Kendial Lawrence from Missouri and veteran fullback Lawrence Vickers in the stable. Randle had limited work in the off-season because of a thumb injury. His cast will be removed Friday.But so far this off-season, Tanner has done everything in his power to ensure he’ll be a part of the team, which opens the 2013 season against the New York Giants on Sept. 8.That starts with his fitness.“I feel a lot better,” said Tanner, who is listed as 5-foot-10, 217 pounds. “I worked a lot on my quickness and explosiveness. I lost a little weight and leaned up a little bit. I’m able to see things and hit the hole without hesitating. Coming in and working hard every day, working with the offensive line and jelling with my team is the big thing.”Tanner spent the off-season sprinting and lifting his way into shape. The early results indicate his work was a success. First-year running backs coach Gary Brown said every aspect of Tanner’s game has impressed him thus far.“From what I’ve seen so far, he looks like he’s in great shape,” Brown said. “He’s studying. He knows what he’s doing and not making any mental errors.”The Cowboys report to training camp July 19. Their first practice is July 21.With Tanner’s physique as proof, the way last season ended served as motivation, both from an individual and team perspective.“We were 8-8 last year. Everybody is hungry,” Tanner said.