Arsene Wenger firmly believes William Gallas is the right man to lead Arsenal both on and off the pitch as the Gunners look to secure safe passage into the Champions League.

Gallas, who only arrived at the club at the very end of last summer's transfer window, was the somewhat surprise choice to replace Thierry Henry as captain following his sale to Barcelona.

The former Chelsea defender - signed as part of the deal which took England full-back Ashley Cole to Stamford Bridge - had made some outspoken comments during the summer in the wake of Henry's departure and the uncertainty surrounding the direction of the club after vice-chairman David Dein left the board last season.

However, Gallas, who turns 30 later this month, has since reaffirmed his own commitment to the club and had made reference to the new challenges ahead in his first programme notes as skipper for the Premier League game against Fulham on Sunday, saying: "I have to give a good example in everything I do."

It is a sentiment which has struck a chord with the Arsenal manager.

"William means he has to be an example everywhere, not only on the pitch - but off the pitch as well and he is right," Wenger said ahead of his side's Champions League third qualifying round first leg clash away to Sparta Prague.

"I do not know how he behaved at Chelsea - but this year he is a very positive influence."

The Gunners boss added: "I was pleased with his attitude and the way he took on his role. I expected him to do that.

"Overall the important thing is that the team has that type of unity and togetherness and desire."

Wenger rejected suggestions the appointment had been made purely as a way of ensuring Gallas toed the party line or was in any way a "special risk".

The Arsenal manager added: "I think the captain is an important position - but it is not as important the team spirit.

"You do not have to overemphasise the importance of the captaincy.

"What is important is that he does what he has to do and not more.

"You need a certain position and a certain experience in the game. That makes it easier."

Wenger, meanwhile, revealed he had now met with veteran midfielder Gilberto to explain the reasons behind his decision.

The Brazil international had stood in for Henry during much of last season, and was somewhat put out to have learned of the announcement via the club website rather than directly from his manager.

Wenger said: "I respect Gilberto a lot. I had a face-to-face meeting with him and told him what I wanted to tell him.

"I have nothing more to say about that.

"I cannot justify every small decision, and explain it to everybody. Things have to stay inside.

"He was not in the (training) group last week, and that is why what happened happened.

"I make decisions and I stand up for it."

Wenger added: "I made my decision and I do not consider whether people are surprised or not.

"When you make a decision it is not to please everybody or surprise some people.

"You make a decision because you just want to make the right one."

Former Sparta midfielder Tomas Rosicky is set to line up against his old club for Arsenal tomorrow night and Wenger knows it is a "big game" for all of the Gunners squad.

He said: "It is a game where he is a bit more under pressure than others because of the extra scrutiny.

"It is a big game for the whole squad, because for us what is at stake is not how will Rosicky look, but whether we qualify or not."

Wenger added: "He is classy and I feel he is at the age where he can get the right balance in the final third.

"He is sharp, quick and lively.

"What we want from Tomas Rosicky is to give key passes and score goals. I am convinced he will."

Arsenal will again be without summer signing Eduardo da Silva, the Croatia striker still hampered by a minor ankle problem.

Similar injuries also kept midfielders Abou Diaby and Denilson out of the travelling party.

Togo striker Emmanuel Adebayor is not yet fit following a groin problem suffered during pre-season and Gilberto has remained in London to continue his delayed preparations after being given an extended break following Brazil's victory in the Copa America.

Wenger is expected to name an unchanged side from the one which beat Fulham with a last-minute winner from Alexander Hleb at the Emirates Stadium in their opening Premier League game.

"I learnt (on Sunday) what I knew before from the preparation - that we had great unity and desire and a great hunger as well," said Wenger.

"This came out in the game because we won a match that we certainly would not have won last year."

(reopens) Wenger knows it will not be an easy ride against the Czech champions at the AXA Arena tomorrow.

"It is a vital match," said the Arsenal manager, speaking at the official UEFA press conference in Prague tonight.

"We want to be in the group stage. Nobody invites you to get in the on red carpet. Sparta are a good team and the first game is very important."

Wenger intends for the Gunners to "fight" on both the domestic and European fronts this season.

However, firstly they must negotiate safe passage past the Czech side.

"This team has big potential - we have been in the Champions League final and want to get back there," said Wenger.

"In the championship in the last two years, we have not fought for that.

"We want to do that again, and so at this moment we are not in a position where we can make any choice."

Meanwhile, Fulham boss Lawrie Sanchez has admitted he may have been hasty in accusing Arsenal of "simulation" during their clash on Sunday.

The former Northern Ireland manager pointed the finger at the Gunners for going to ground too easily.

But now Sanchez has reviewed the incidents, he has apologised for his outburst, admitting "sometimes I shoot from the hip, and in that instance perhaps I should have waited a little longer".

Wenger was disappointed by the initial post-match comments.

The Arsenal manager believes it could have influence on referees in future games.

He said: "I tried to look as objectively as I could at the tape, and I could not see anything.

"I saw only one real dive - it was not an Arsenal player, it was [Steven] Davis.

"We did not get a penalty (for the challenge) on Hleb - all the media saw it was a penalty.

"Sometimes your job is when you are attacked in the right way, it is to put something right.

"There was only one guy who tricked, and that was Davis."