Republic of Ireland captain John O\'Shea knows there is room for improvement despite his side producing a respectable display in Belgrade. Injuries to a number of players, Shay Given\'s decision to retire from international football and with Robbie Keane and Damien Duff given leave of absence, boss Giovanni Trapattoni\'s line-up was an experimental one for last night\'s 0-0 friendly draw with Serbia. But it was a test Ireland\'s players emerged from unscathed, considering the pain still runs deep following their disappointing UEFA EURO 2012 finals campaign in which they lost all three matches. Veteran Italian Trapattoni, renowned for his rigidity with regard to a 4-4-2 formation, even pushed the boat out by playing 4-1-4-1 - although later insisted it was 4-3-3, though that is debatable. Regardless, ahead of the opening FIFA World Cup™ qualifying match with Kazakhstan on 7 September, there were signs of hope. Sunderland defender O\'Shea, wearing the skipper\'s armband for the first time given the list of absentees, was happy enough. \"We needed to get [the EURO] out of our system,\" said O\'Shea. \"This was always going to be a difficult place to come to, Serbia away, and playing with a newish system and with some new lads. But I thought James McCarthy was fantastic, coming in and doing a great job, and James McClean as well playing in an unfamiliar position.\" \"We were quite comfortable in the game, and we caused them some early problems, although we would have liked to have created a few more clear-cut chances. We have room to improve, particularly after having only one day to work on that system, which some lads play at their clubs and some don\'t.\" It is likely Trapattoni, with what he will hope will be a near full complement of players to choose from for the trip to Astana, will revert to type, not wanting to take risks, and again play 4-4-2. The 73-year-old Italian gave little away as he said: \"It was important we tried a different tactical approach. \"I will have to digest what I saw and then I will think what to do for Kazakhstan next month. But this was a good result for us because we have young players, and also players not in condition. \"It was a good result against a good Serbia team that knows each other well and are used to playing well together. This friendly was important for us to test the young options, but we don\'t forget the older players at this moment.\" At least in Keiren Westwood it appears reliability is still in evidence in the goalkeeping department, despite Given\'s exit. The 27-year-old Sunderland goalkeeper produced two fine saves, one especially in the 71st minute to deny Zdravko Kuzmanovic from a 20-yard free-kick, to give Ireland a deserved draw. Trapattoni said: \"This was a particular moment for him after the news about Shay. I was sure he could be a substitute for Shay and he showed us in this game we can trust him.\" From : Fifa