Foakes enjoyed what Buttler described as "probably the best debut ever in Test cricket" in Galle. After becoming the first England keeper to score a century in Asia (and only the second from any nation to make one on debut), Foakes equalled the record for the quickest dismissal by a keeper on debut - he claimed a catch from the second delivery of the innings - and soon afterwards completed a stumping, too.
It left Buttler accepting that he had been set an "example" of the "level you need to get to" as a keeper.
"Ben had a fantastic game in Galle," Buttler said. "Probably the best debut ever in Test cricket. By the second afternoon, he had a hundred, a stumping and a catch.
"He is a fantastic gloveman. It's a good reminder and a little wake-up call that he's the level you need to get to. Just looking personally, he's a great example to someone like myself as to where I need to get to."
While Buttler accepted there were times when his role as keeper helped him relax as a batsman, he also argued that giving up the gloves had allowed him more time to work on his batting.
"If I look back to the Ashes in 2015, I didn't get the balance right between practising my batting and wicketkeeping," Buttler said. "I was very wicketkeeping-orientated. My batting faltered. I've read Matt Prior saying in the past that as a wicketkeeper-batsman, you're going to train harder and longer than most.
"There are days when being an all-rounder is an advantage to you. It makes you more relaxed. If you don't have a good day with one discipline, you can affect the game with the other. Or if you do one really well in one, you can take that confidence into the other.
"But with the summer just gone, I've really enjoyed the role in the side [as a specialist batsman]. With more emphasis on my batting, I've really enjoyed the improvements there."
Meanwhile Joe Root hinted that Jonny Bairstow might have to sit out the second Test as his ankle injury heals. While Bairstow batted and fielded in training on Monday, England want to ensure there is no chance of a setback.
"It's quite a serious injury," Root said. "I think he's still a week or so off being 100 percent.
"He's mad keen to get back out there and play. He is pretty much close to flat out as he can be at the moment in the fielding and with his batting. It's a good sign."
Root also explained the reasoning behind confirming Foakes as keeper for the second Test.
"Ben is going to keep," he said. "We've come to Sri Lanka to win this tour. And in these conditions, I think Ben is the best option behind the stumps.
"Jonny is a fine keeper and what he's done over the last couple of years has been exceptional. He's pretty much been faultless and, long-term, I see him as a focal part of the Test team.
"But this is a great opportunity for Ben to show his ability and I think you've got to reward a performance like last week."