Ramsey had an intense international break and started two games for Wales.
And the midfielder was in the Arsenal starting lineup at St. James's Park in a three-man midfield with Matteo Guendouzi and Granit Xhaka.
Xhaka's and Mesut Özil's second-half goals brought Arsenal into the lead. This allowed Emery to eliminate Ramsey and exchange with Danny Welbeck with ten minutes remaining.
Ciaran Clark scored a late goal for Newcastle, but the Gunners held their third game in a row.
And after the match, Emery confirmed that Ramsey had told the bank that he wanted to be replaced.
"He played two games with the national team and then he played 80 minutes with us, so he asked us to change him," he said.
"It's not a big problem, but he was tired, I think it's not a problem."
The victory for Arsenal was also the first time since May 2017 for away wins.
But Emery said his players need to push themselves and not become complacent.
He said, "We have to push for ourselves and for the challenge.
"One challenge is to achieve better performance, be more competitive and have many chances to win, but this must be done consistently and our requirements are very difficult.
"We have to continue because we have to prove we are more competitive, and I think that's one of the important things the team has shown us."
Arsenal begins its European League campaign on Thursday against the Ukrainian side Vorskla.
But Emery kept his cards close to his chest, whether he wants to make his debut for Bernd Leno.
He said, "We will change and use many players for different competitions, but we are just thinking about the best performance we can win on Thursday.
"Every competition is for me [doing as well as you can] Usually you use another goalkeeper [other] Competitions, but it's about giving [your best] Performance."