Arsenal captain Martin Odegaard says they're well aware they face a Nottingham Forest on the up today.
Writing in his match programme notes, Odegaard said: "We played against Nottingham Forest last season when they knocked us out of the cup, so we know to expect a really big test today.
"I didn't manage to watch their game against Liverpool last weekend, we were training at that time, but of course it's a great result for them, and tells us what we have to be ready for today.
"We know they have a lot of quality players. They have changed a lot since we played that game in the FA Cup, bringing in a lot of signings, so I expect it to be a very different team to the one we faced in January.
"It looks like they have added a lot of individual quality to what they already had, and like every team in the Premier League, they have shown they can beat anybody.
"I played the whole of that FA Cup game last season away at Forest, and I was very impressed with them that day, so if they have improved even more since then, then for sure they will be a difficult test today.
"They will be highly motivated coming to the Emirates today, with the confidence of their result last weekend as well. It's up to us to get back to winning ways in the league."