Arsenal  v PSV Eindhoven:Arsene Wenger is not known as a gambler but, with Arsenal attempting to salvage a season which threatens to be their most disappointing for a decade, he is considering a roll of the dice.

Thierry Henry rejoined training only on Monday after two weeks out with the back and hamstring injury which has disrupted his season, but Wenger is set to risk losing his captain for a long period to win a match which could rescue the club's season.

Not since 1996-97, when Wenger became Arsenal's manager part way into the season, have the club's chances of winning a major trophy ended before April. To avoid that fate tonight and reach the quarter-finals for the third time in four years, they must overcome a 1-0 deficit against PSV Eindhoven.

"If it [ Henry's injury] gets worse after the game, we will stop him completely until he is completely clear. There is no risk for his health, but it is just it could get worse again after the game and then [ we] start from scratch," said Wenger.

"From his back his hamstring is tight. That has happened the whole season. He is vital because he can score and he has a psychological impact on opponents as well. I'm very happy that I have him available."

Arsenal trail after Ecuadorian midfielder Edison Mendez's low drive in the opening leg in Eindhoven two weeks ago. That win was PSV's first in five attempts against the London club.

Wenger conceded that Henry's inclusion in his squad was a major boost to morale as Arsenal bid to follow up Saturday's 2-1 victory over Reading, their first win in five games, following three successive defeats.

"He gives us a capacity to make the difference," said Wenger. "And for his passing, his goal-scoring skills - a player like that is vital in a game when you have to score goals. He did not practice at all for the last two weeks, but he did a few gym sessions without running, you know, and I don't think he lost too much (fitness).

Henry, scorer of 10 goals in 17 Premier League appearances this season, has scored 42 goals in 84 Champions League games.

PSV coach Ronald Koeman acknowledged Henry's presence on the pitch could present difficulties for his side.

"A fit Henry is very difficult to defend against and that could be a problem for us," Koeman said.

"Psychologically for Arsenal it is very important that Henry is there. Basically, he is the face of the team and the other players play better when he is on the pitch."

Koeman remained confident, however, his side could claim a place in Friday's quarter-final draw in Athens.

"I won't reveal now the way we will play, but it could be the same as the first leg. However, we can also choose to play a different tactic and maybe go a little bit more for goals, compared to how we were at home," he said.

"But I don't expect Arsenal to play any different to their usual style, which is always to score goals."

Apart from Henry, Wenger is also depending on Freddie Ljungberg. "In the last few games he is getting back to his best; Freddie likes March, when it becomes very important. He is a winner and has those extra little resources in the big games to make the difference."

Arsenal must score twice or rely on penalties to progress but can be buoyed by their unbeaten record at the Emirates Stadium as well as the fact that they have come from behind to force results at home on 12 occasions this season. Wenger expects PSV to be cautious again tonight.

He is adamant he will continue the defence of his comments in the aftermath of the League Cup final."You might think I am paranoid; I'm not. I speak what I see. Watch the tapes. If some people are not happy, they are not happy."

Wenger said he expected "another tactical match". "They will defend and catch us on the break, as in the first game," he said.

Wenger said that it was essential Arsenal defended well and remained patient, relying on the quality of their football to produce chances and goals.

"We have to find solutions, be creative around the box with the speed of our combinations and ruthless when we have a chance," he said.

Arsenal are unbeaten in 14 Champions League home games since losing to Chelsea in a quarter-final second leg three years ago. They have not lost any of their 21 competitive games at their new Emirates Stadium this season, but have had to fight back after falling behind 11 times.