EAST RUTHERFORD, N.J. -- Many three-year NFL veterans use the preseason as a tuneup.But thats not the case for New York Giants running back Andre Williams.Williams is in a tough competition for a spot on the teams final 53-man roster that will kick off the season Sept. 11 against Dallas.Williams, a fourth-round draft pick out of Boston College in 2014, struggled last season, rushing for only 257 yards and one touchdown. Williams averaged just 2.9 yards per carry, and the team drafted Paul Perkins out of UCLA in the fifth round.Theres only room for so many running backs, so Williams knows that he has no guarantees. Orleans Darkwa, who had 153 yards on 36 carries (4.3 yards per carry) and a touchdown last season, is also in the mix.Im supposed to be here, Williams said Friday night after leading the Giants with 41 yards on nine carries in a 27-10 loss to the Miami Dolphins in the preseason opener.I dont feel like I have to prove anything. The only thing I have to prove is prove to myself that I can be here and do the job.Williams also saw some time on special teams Friday, trying to show his versatility.I did a lot of things, Williams said. I showed I could get to the outside well. It was a big emphasis for us to win the outside zone. I had to get to the gap and get outside. I always thought I was fast enough. Being able to get out there was big for me.Williams broke a big run for 16 yards early in the game.I think Im able to carry my weight better now, Williams said. Every time I get on the field, theres a balance between knowing that I have do to certain things and going out and having fun.Perkins also showed a good balance of speed and strength, gaining 36 yards on seven attempts (5.1 yards per attempt) Friday night, making the competition for that roster spot that much more interesting.Darkwa, who was a special teams stalwart last season, had two carries for 16 yards Friday.Another rookie who had a stellar game was linebacker B.J. Goodson, the fourth-round pick out of Clemson. Goodson tied for the team lead in tackles with six with veteran Mark Herlizch. Goodson also had two tackles for losses.It felt good to be able to do something and fly around out there, Goodson said. Im very grateful, because not a lot of guys get this opportunity. I just wanted to do my best and do whatever the coaches seem fit.Rookie wide receiver Sterling Shepard had the catch of the game for the Giants, a diving grab along the sideline for 24 yards, before leaving with a slight groin injury.Its nothing serious at all, Shepard said of his injury. Its just a little sore. Ill be all right.As for his acrobatic catch?Its just something that I can do, Shepard said. I felt like I could go and get it. I think whatever happens in practice can carry over to the game. I was doing well in practice. This was just preseason. I have a lot left to do.But the Giants struggled in some aspects of the game, especially the play of backup quarterback Ryan Nassib.Nassib, a fourth-round draft pick four years ago, has never had a chance to play much because of Eli Mannings durability.But Nassib got the chance to play most of the game Friday night, but didnt do much to impress Ben McAdoo, who made his head coaching debut.Nassib completed just seven of 15 passes for 75 yards, throwing two interceptions and fumbling once. Nassib appeared jittery and completed just one pass more than 20 yards, the 24-yarder to rookie Shepard in the first quarter.Nassib drove the Giants 39 yards on the first drive -- then a total of 40 yards over the next 10 drives. The Giants fumbled a total of six times in the game.Ball security is the No. 1 priority in this league and I didnt do a good job of that, Nassib said.We have some things we have to work on. Turnovers are unacceptable. You never go into a game expecting to throw two interceptions. Obviously, when you fail, its disappointing and frustrating. I just have to bounce back and get back out there.McAdoo was not pleased with the offensive performance.We left six balls on the ground and threw two interceptions, McAdoo said. Thats not the way we wanted to start the season. We wanted to run the ball and d