By Rob Kelly

For Damian Martinez, life is good. The easy smile on the young goalkeeper’s face speaks volumes: his time is coming, his star is very much in the ascendant. All he needs is the opportunity to show what he can do.

The 20-year-old is an outstanding prospect, a charismatic presence off the pitch and an athletic, arresting sight on it. Standing at 6ft 4in and possessed of superb reflexes, he has all the attributes to make it to the very top.

But a few short weeks ago, the smile was wiped from Martinez's face as he was sent off in his first appearance at Emirates Stadium.

Just 25 minutes into Arsenal’s opening game in the Under-21 Premier League against Bolton, the Argentine brought down the onrushing Chris Lester in the area. A red card and penalty decision quickly followed, and Martinez was soon trudging his way disconsolately to the changing rooms for an early bath. It wasn’t meant to happen like this.

Even recalling the incident a month later sees his mood temporarily darken.

“It was really disappointing because I didn't touch the striker and he was offside by about five or six yards when we checked the video later,” Martinez told Arsenal.com.

“As soon as I saw Gerry [Peyton - goalkeeping coach] I told him, ‘I didn’t touch him, I didn’t touch him’. But there was nothing I could do.

“At least the team still won the game 3-1, and the video showed he was offside and I hadn’t fouled him. But it was really disappointing for me to get sent off at the Emirates.”

The incident was a rare moment of discomfort for Martinez since his arrival at the Club from Independiente in August 2010. Since then he has made giant strides forward, so much so that he even won a call-up to the full Argentina squad in June 2011.

It proved to be an invaluable learning experience for the young goalkeeper as he trained alongside the likes of Lionel Messi, Sergio Aguero and Carlos Tevez before their friendly matches against Nigeria and Poland.

“I was 18 years old when they called me up, and my first impression was, 'What? No way!' - I couldn't believe it,” he said. “To play alongside all those great players was amazing.

“It is unbelievable against Lionel Messi in training, you cannot save anything! You never know what to do. When Messi is one-on-one with you, you can't do anything because he is just too good. But it was a fantastic experience to play alongside all of those players and make friends with them.”

Since then he has been named on the bench for last season's first team’s matches against Shrewsbury and Leeds, and against Stoke and Liverpool this term. He appears to be on the cusp of his breakthrough.

“I am having a great moment right now,” he said. “I was very happy to be in the squad against Stoke and at Anfield.

“It makes me even hungrier to play for Arsenal and shows me that I can do it. I just need to keep working hard with Gerry and Tony Roberts. They tell me I am doing well and will get my chance.

“Hopefully I can keep going and will be on the bench again soon, and maybe even start in the Capital One Cup. I will just work as hard as I can and see what happens.”

Martinez played in the under-21s’ 1-1 draw against Norwich on Monday and will may well get a further opportunity to prove his credentials at West Ham tonight. And no one would bet against the big Argentine taking another sure-footed step towards the first team with a strong performance.

After all, once you have faced the magical Messi, nothing is likely to faze you.

Remember we will have live tweets from Arsenal Under-21s’ game at West Ham from 6.55pm (UK time) on the @ArsenalLive account

Copyright 2014 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source 21 Sep 2012