The France international was not part of the Arsenal team that made the trip to Spain to face FC Barcelona in their final pre-season friendly on Sunday night.
Lacazette was thought to be nursing a minor injury to keep him sidelined from the clash against the La Liga champions in the Gamper Trophy at Camp Nou.
The French striker has established himself as a key part of the Arsenal team since Emery took over the reins from Arsene Wenger at the end of the 2017-18 Premier League season.
Speaking at his media conference following Arsenal’s 2-1 loss to FC Barcelona in their final pre-season friendly in Spain on Sunday night, Emery said:
“Hopefully he could be available for the match against Newcastle.
“The doctors, they are optimistic. We are going to wait. The next days are going to be very important to see how he is going to progress with his injury.
“But I am really, really happy with other players also. If he is ready for Sunday, perfect. If he isn’t, then for the next.
“We need now to have a very competitive team, with the players ready forth next matches but above all to create a mentality to start strong and find our best performance in the next match.”
Arsenal have been busiest of the top-six Premier League clubs in the summer transfer window.
The Gunners started their summer spending with the addition of Brazilian teenager Gabriel Martinelli from South American side Ituano.
Arsenal spent a reported £36m on Saint-Etienne centre-half William Saliba before loaning the teenager back to the Ligue 1 side.
The north London side signed Real Madrid midfielder Dani Ceballos on a season-long loan last month.
And Nicolas Pepe completed a club-record £72m switch to Arsenal from Lille last week.
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