McGinn is back in full swing for Villa after almost two months out with a knee injury, during which their form collapsed, and scored his second goal of the week as his side beat West Ham 2-0 on Sunday.
Victory consolidated Villa’s position in the top four as they hunt Champions League qualification.
Emery said: “His challenge is to add numbers. Two years ago I told him at the beginning of the season, if you add numbers this season, 10 goals and 10 assists, we can achieve our objective.
“This year is something similar. He is adding numbers and with those numbers we can keep the position we are in now."
Villa were also able to call on influential midfielder Youri Tielemans against the Hammers following his return from an ankle injury.
Emery added: “Very important. He played after two months out. Now he is going with his national team and he will come back again in two weeks, ready to add to us his quality and leadership.
“He is very important as a quality player, with his mentality as well.”