Arter, 26, joined from non-league Woking in 2010 but will now rub shoulders with Arsenal star Wilshere.
He said: “I've got confidence in my ability that Jack signing won't push me to the bench.
“I've been part of the club for the last six years now. Every year the manager has brought in added competition.
“Up until now, I haven't missed a game through anything other than an injury. So I'm thankful for the manager always playing me.
“The competition has got even harder. That's what I thrive on. I want to become a better player and I'm only going to do that if the manager brings in players of Jack's ability.
“I get a little bit of stick from the lads when we are signing players for millions and there is me priced at £4,000.
“But for every player there is a different story and I'm really proud of how I've got to where I am. It's been a lot of hard work and continues to be."