Arsene Wenger says there is no chance of Arsenal taking Middlesbrough lightly in their FA Cup fifth round tie on Sunday.
Arsene Wenger: Boro will be tough foe for Arsenal
The holders take on Aitor Karanka's high-flying Championship side in the last eight looking to avoid the same fate as Manchester City, who were knocked out by Boro in the fourth round.
That win is part of a 10-game unbeaten run for the league leaders, who claimed top spot in midweek when they edged past Blackpool 2-1.
"We will not have the excuse to be surprised because they beat Manchester City in a convincing way," Wenger said.
"That is a good warning for us. We are at home, we have a possibility to go to the quarter-finals so we cannot be surprised by them, that's for sure.
"It's a big challenge, but big opportunity as well. That's how we have to look at it. We have the luck with the draw to play at the Emirates so let's take this opportunity."
Arsenal are still fighting on three fronts, with their Champions League knockout tie against Monaco on February 25, and Wenger is pleased with the depth of his squad despite a number of absentees.
Aaron Ramsey is the latest player to go down with injury, having hurt his hamstring against Leicester in midweek, and he joins Alex Oxlade-Chamberlain (groin), Mikel Arterta (ankle), Mathieu Debuchy (shoulder) and Abou Diaby (calf) on the sidelines.
"We have the squad to do it," Wenger added. "How dedicated, how focused, how motivated, how united we'll be until the end of the season will decide that.
"This is a period where you need more from your players than usual, because it's the last four months of the season and you need everybody to give a bit more than they're used to."