The Spain international has scored an impressive eight goals in 23 Premier League appearances for the Gunners after completing a summer move from Malaga.
The 28-year-old’s first strike in the English top-flight came in a 2-0 victory at Liverpool in September, and Allen is aware of the threat that the playmaker poses.
“He’s been a great addition to them – a technician with great quality,” Allen told Liverpool’s website.
“One of his biggest attributes is the fact he plays off both feet, so he’s a danger for us and someone we’ll have to prepare to face and make it as difficult as possible for him to perform.
“We’ll be earmarking him, no doubt.”
Allen also believes Liverpool must disrupt Arsenal’s possession-based style of play if the Reds want to secure successive Premier League victories at The Emirates.
“You’d like to disrupt their passing game as much as you can. That’s key to the way that they go about their business and want to control the game.
“At the same time, we focus on ourselves. You can sometimes go into these games a little too worried about the opposition, and that can take a little edge off your own team.
“They are a team that can do that to any team on their day. They’ve got quality; they have done for many years.
“But nothing changes from our point of view. We’re ready to go out and give 100 per cent – if everyone performs to the best that they can, we can get the result.”