Arsenal legend Thierry Henry was impressed after Liverpool's 4-0 win against Barcelona on Saturday and admits that the Gunners should be careful next week.
Arsene Wenger's men host the Reds in what will be one of the most fascinating encounters on the opening day of the English Premier League.
Arsenal will be without a number of key players with Calum Chambers expected to start in central defence.
"I would be [worried about Liverpool]," Henry is quoted as saying by Goal.
"It was a friendly game [against Barcelona]. We know Arsenal are going to try and keep the ball, pass it around but Giroud won't be involved. All the guys that went far in the Euros too. I would be worried to play that Liverpool side I've seen today.
"Yes, it will be a concern [some of Arsenal’s players only just returning]. The only positive thing for me is that the game is at the Emirates.
“I would like to think that Arsenal would have enough to beat Liverpool but from what I've seen today, and yes we can say Barcelona were not at their best but I like the way Liverpool set up their team.
“I like the way they play - high pressure, getting the ball back. They had an idea of what to do with the ball as soon as they got it back. So watch out!"