Manuel Almunia feels Arsenal must develop a "killer instinct" in front of goal if they are to sustain a genuine title challenge this season.
The Gunners missed the chance to leapfrog Chelsea to the top of the Barclays Premier League on Saturday night when they conceded an equaliser at Sunderland in what was the fifth minute of added time.
Despite being reduced to 10 men when midfielder Alex Song was sent off at the start of the second half, Arsenal had enough chances to have already secured the three points well before the home side's late rally - especially when awarded a penalty which Tomas Rosicky blasted over.
Goalkeeper Almunia feels Arsene Wenger's men have the quality needed to last the distance, but cannot afford many more wasted opportunities if they are to get ahead of Chelsea and Manchester United.
"In the last second of the game, it is a big kick against us, but this is football," Almunia told Arsenal TV Online.
"Last season we won some games in the last few minutes, and this can happen in every game.
"Even though we were winning 1-0 with not much danger in our box, we needed to get another goal to make sure the three points would be for us.
"I think we have to be more focused in the final few metres and have to have a killer instinct [in front of goal]."
Almunia added: "Each player is a bit older every year, and every year we are learning a bit more. Football gives you experience.
"We have had the same players for a few years, we know each other very well and play fantastic football - but still we have to get this point of maturity which will give us the step forwards."
Had Arsenal held out, it would have been a third clean sheet for Almunia from six appearances.
The Spaniard's position as Wenger's first choice was the subject of speculation over the summer, as Arsenal had bids for Fulham's Australia international Mark Schwarzer turned down.
Wenger feels both Almunia and his deputy Lukasz Fabianski - who has also had his fair share of criticism - coped with the situation well, hailing the Spaniard's form as "outstanding".
Almunia, though, maintains it is nothing about proving anybody wrong.
"I am just trying to do my job for Arsenal, and am very happy," he said.
"That is my only worry, to be well, to be focused and to feel comfortable on the pitch.
"I think I have started very well.
"I try to be away from comments, but it is good the boss speaks well about me and I appreciate it."
Captain Cesc Fabregas is to be assessed after suffering a hamstring problem in the course of scoring a freak goal at Sunderland, but along with other senior men would have not been involved in tomorrow's Carling Cup tie at Tottenham anyway.
Meanwhile, the Football Association have yet to confirm whether any disciplinary action will be taken against Wenger, who confronted fourth official Martin Atkinson after Darren Bent's goal came some 15 seconds after the allotted four minutes of added time had been played.