Arsene Wenger admits he will strengthen the Arsenal squad “where it needs” this summer in what is set to be one of the key decisions of his tenure.

The Gunners look to be heading for a sixth consecutive season without silverware after a last-minute defeat at Bolton left them nine points behind Barclays Premier League leaders Manchester United with just four games left.

Only eight weeks ago, Arsenal appeared well on course for a much different outcome before they suffered a shock Carling Cup final defeat to Birmingham at Wembley, went out of Europe to Barcelona and then lost their FA Cup quarter-final at Old Trafford.

Six draws from the last nine of an unbeaten 16-game Premier League run, which ended yesterday, saw what had looked to be a sustained title assault fail to last the distance once again.

Wenger cut a forlorn figure at full-time at the Reebok Stadium, as the reality of his young squad’s latest failing sunk in.

The Gunners boss has endured great criticism of his unwavering faith in youth, with fans and pundits alike calling for him to add some steely experience to all that potential.

While Wenger is unlikely to raid his �40million warchest for just one marquee signing this summer, it is now highly probably a couple of more mature players will be brought in to help the current generation win that first illusive trophy.

“We have the quality, that is for sure. We have to strengthen the squad where it needs and make the right decision on that front. It (transfers) is always in my mind every day,” Wenger told Arsenal TV Online.

“The team have had an outstanding attitude and will not be rewarded because of small things, but small things cost you.

“It is frustrating because the team has produced the efforts.

“We have to be realistic that it (the title) is very unlikely now, but we have to finish as well as we can.”

Next up for Arsenal is the visit of United on May 1, in what Wenger had hoped could prove a title showdown, but where now an Arsenal victory would only seem to serve as a delaying tactic for the Red Devils’ coronation or give London rivals Chelsea a shot in the arm.

Despite all of the now perennial criticism over his young squad, Wenger maintains Arsenal’s philosophy stands true.

“If someone can convince me that the principles are wrong I am ready to change, but I feel we try to play football the proper way,” he said.

“When you don’t win you question your principles, but you have to give yourself the right distance to see what is right and wrong in what you do.

“I think if something is wrong in our team, it is not the principles in playing our football.”

Wenger, however, accepted shortcomings at the back have proven too costly, Arsenal without injured centre-half Thomas Vermaelen for most of the campaign.

“We have not been stable enough defensively,” he said.

“The numbers are the numbers - this week we have conceded six goals and you cannot afford to concede six goals in April in three games and win the championship.

“Defensively we have been too frail this season.”

Wenger may not have delivered a trophy since Patrick Vieira lifted the 2005 FA Cup in Cardiff, but few can accuse the club of standing still.

Arsenal have moved from Highbury to their new 60,000-seater home at Ashburton Grove, which in the long-term will secure their self-funding status, while the Gunners also reached the 2006 Champions League final.

Wenger has overseen consistent qualification for Europe’s lucrative elite club competition in each of the past 15 seasons, while his transfer spending is in credit - unlike all of Arsenal’s title rivals - and has tied-up key men such as Cesc Fabregas on long-term deals.

Former Arsenal goalkeeper Bob Wilson believes calls for a change in the dugout are wide of the mark.

“He is not fireproof, nobody is, but Arsene is an intelligent man and he will say when he has taken them as far as he can,” former Scotland goalkeeper Wilson, who won the double with Arsenal in 1971, told BBC Radio Five Live.

“I don’t think the board will ever sack Arsene, unless there is a dramatic slump in the manner they play.”

Wilson added: “Arsene has a complete aversion to paying double the price for British players, but he has to swallow his pride on that because there has to be a more British feel to the team.”