Trippier lashed home his second direct free-kick in a week to earn Eddie Howe’s men all three points at St James’ Park – but ended the afternoon on crutches.
The January arrival from Atletico Madrid went down early in the second half and was replaced by Emil Krafth.
He limped down the tunnel and was swiftly taken to hospital for a check-up.
“Kieran got stamped on,” said Newcastle boss Howe. “He couldn’t continue because of a problem on the top of his foot.
“He’s gone for an X-ray at the hospital, and we’re keeping everything crossed that there’s no broken bone there.”
Newcastle’s medical staff placed Trippier’s left foot in a protective boot and he was reported to have attended hospital on crutches. He returned to St James’ Park half an hour after full time.
Were Newcastle’s worst fears to be realised and Trippier was ruled out for a number of weeks then it would be a bitter blow for their battle against relegation.
Sunday’s victory over Villa was the club’s third on the bounce and they remain unbeaten in the league this year as they move four points from safety.
Trippier’s presence at the back has helped Newcastle secure clean sheets over both Leeds and Villa, while it was a Jamaal Lascelles own goal that briefly gave Everton the lead in their encounter on Tyneside, in which Trippier also found the net in a 3-1 win.
His goal on Sunday came after a lengthy pause for a VAR check after Calum Chambers had upended Joe Willock on the edge of the penalty area. And while the home fans bemoaned the reversal of referee Craig Pawson’s decision to award a penalty, it made Trippier’s subsequent thumping free-kick that whistled past Emiliano Martinez all the sweeter.
“It was a strange one, when the penalty is not given you are naturally disappointed. Since Kieran has come in he has been incredible for us,” said Howe.
“Three more points feels good from where we have come. But even in this good moment we are very calm but very pleased.
“We didn’t give up too many chances to Aston Villa. It was a tight game and in weeks gone by we wouldn’t have won this game. There is still a heck of a long way to go.
“There are lots of things we can improve. We defended heroically at times but I feel we have a lot to do still. We know we are in the early stages but we’re pleased with progress we are making.
“The crowd has been like this with team and me from the moment I came in. I can’t thank them enough.”
Newcastle also lost Javier Manquillo due to an ankle issue.
“He landed awkwardly on his ankle, so I think there’s a ligament problem,” Howe said.