London, Feb 22 (IANS): Former Arsenal star Thierry Henry believes that the Gunners must be prepared to sacrifice their attacking game and defend as a unit if they have to edge past Barcelona in their Champions League round of 16 first-leg encounter.

Arsenal take on the defending European champions at home on Tuesday.

"They (Arsenal) have to accept they will probably only have 30 per cent possession and must be so efficient when they do get the ball. The whole team must defend more as a unit and the wingers must tuck in and play more in their own half," Henry wrote in a column for the Sun on Sunday.

"You very rarely get the chance to play against Barcelona, so you must be prepared to sacrifice parts of your attacking game, home and away."

The 1998 World Cup winner also said that Arsenal must make best use of the few chances they will get against the Catalan giants.

"Arsenal must be brave on the ball. They need to stay compact, play on the counter and score every time they get in their penalty area," said the 38-year-old.

"They can't be exposed in the middle and must force Barcelona to run back 60 yards before they get the ball. If you allow them to stay in your half for wave after wave, it becomes almost impossible to defend," concluded the Frenchman.