Cristiano Ronaldo displayed "unacceptable" behavior by walking off as Manchester United were putting the finishing touches to a victory over Tottenham, according to Gary Lineker.

The Portugal great, who was an unused substitute in Wednesday night's game at Old Trafford, walked along the touchline and down the tunnel before full-time.

According to a report in The Athletic, Ronaldo kept going and immediately left the stadium, rather than celebrate with teammates after what was arguably the team's best performance of the season.

United were excellent as they secured a sixth Premier League win of the season to go fifth in the table, thriving without having to call on the 37-year-old Ronaldo.

The fixture was one in which Ronaldo hit a hat-trick last season, but he was a spare part in United's 2-0 win this week, only for the early exit to draw attention to himself again.

United manager Erik ten Hag said he would "deal with" the matter on Thursday.

Former Tottenham and Barcelona striker Lineker, presenting the BBC's Match of the Day program, suggested Ronaldo had overstepped the mark.

"Cristiano Ronaldo: now we all know what a great player he's been and stuff like that, but walking off the pitch as a substitute with two minutes to go, before the game is finished, I'm sorry, but that's unacceptable. That's poor, isn't it?" Lineker said.

Pundit Micah Richards, a former Manchester City defender, agreed Ronaldo was out of order.

"It's so poor," said Richards. "For someone we've looked up to for so long, one of the greats of the game, to do that when your team are winning, making it about him, it's unacceptable."

United were terrific in front of their home fans, racking up 28 shots to Tottenham's nine, with goals coming from Fred in the 47th minute and Bruno Fernandes in the 69th. Their defense was also impressively stout, allowing Tottenham to only accumulate 0.48 expected goals.

Speaking to Amazon Prime after the contest, Ten Hag said dealing with Ronaldo was a problem for another day.

"I will deal with [Ronaldo] tomorrow, not today," he said. "Today we celebrate this victory, and now we have to recover from this."

Ten Hag said in a subsequent press conference that he chose Marcus Rashford rather than Ronaldo because of the England forward's pressing qualities.

"What we needed was we needed good pressing, you need a good counter-press because from there you can create chances," Ten Hag said.

"Offensive-wise you need dynamic, so that is what Marcus can give you in a game."