The 28-year-old made the move to Villa Park for £20m this summer after proving his worth in the first team for the Gunners in the back end of last season.
Martinez grasped the opportunity afforded to him by Bernd Leno’s injury and impressed for Arsenal as they won the FA Cup and then the Community Shield.
With Leno back from injury, Martinez’s place was under threat and he chose to make the switch to Villa, which he believes is actually a step up from his time at the Emirates.
‘I’m in the best shape of my career and when I didn’t have the security of that game time, I wasn’t sure about staying,’ Martinez told Sky Sports. ‘I’m fighting to be Argentina’s number one, that’s my dream.
He is now relishing being the undisputed number one with Villa, winning his first two league games with his new side, without conceding a goal.
‘People don’t realise how much I’d been fighting to get on the bench. I had nine goalkeepers in front of me,’ the stopper explained.
‘Once on the bench, I wanted to be number one. Once I got the number one shirt, and I wasn’t sure I was going to keep it, I said I’ll go and be the number one.
‘My ambition was always trying to be number one at Arsenal, coming through their academy was not easy. People that talk outside of football know nothing about football.
‘I want to be in Europe with Villa next season. Everyone at the club thinks we can have a great season, which drives me forward. We’ve got two wins on the bounce, so we’ve got nothing to lose against Liverpool.
‘If you want to achieve something in the league, you have to beat the best, which is what we will try to do on Sunday.’
Martinez’s clean sheet record will be under threat on Sunday night when Aston Villa host the Premier League champions Liverpool.