The Ecuador international was man of the match in the victory against Bolton and is emerging as a constant threat down the right flank.
Being deployed at full-back around Christmas time may have provided an extra spur for the winger, according to his manager, and his marker at the Emirates Stadium could be in for a difficult afternoon.
"Valencia is back to his best form now," stated the boss. "It took him a bit of time to get over his injury. Really he's had two injuries with us and this one took him a bit of time to come back from.
"Also, because Nani's form was so good at the time, I was playing him right-back in some of the games and he had to cope with that. Maybe he was thinking: 'Am I going to get in my normal position again?' His form has got better and better.
"Ashley Young got injured and I moved Nani to the left-hand side and you've seen Antonio come right back to his best form. That's pleasing as he's a good boy, a tremendous professional, who works very hard at his game.
"He tries to go past his man most of the time but he's clever enough to come inside and can pass a ball. He's a good passer actually. He's got a lot going for him.
"Last week, against Bolton, obviously that was him starting to show his real top form. He's been threatening it and we've seen him gradually getting to that point where he's in really good form now."