There are some things you just can’t polish, as the saying goes, and this desperate and dreary season for Manchester United is one of them.

The win over Brentford in their last home game on Monday night could no longer cover the cracks that have emerged in the past nine months than it can silence dissenting voices from the stands.

There were more protests outside Old Trafford before kick-off, and anti-Glaser chants were heard moments after Bruno Fernandes, Cristiano Ronaldo and Raphael Varane scored to secure a comfortable win.

Cristiano Ronaldo was the star of the show as Manchester United beat Brentford 3-0 in the Premier League on Monday

Ronaldo scored the second goal for United from a penalty kick after winning the penalty kick after a foul by Rico Henry

The 37-year-old forward sent the goalkeeper the wrong way to score his 24th goal of the season in all competitions.

Ronaldo prepares to do his iconic celebration after doubling the lead on the night shortly after the first half ended

Ronaldo, in particular, has been excellent here as he continues to mock those who question his true value to this club.

United were bright, too. They looked like a team determined to come out on top at Old Trafford one night when a number of them were playing here in red for the last time.

Change is coming under new director Erik ten Hag and it’s not a moment too soon. The best-case scenario now is that United score the fewest points ever in the Premier League by winning the remaining two away games against Brighton and Crystal Palace, and then qualify for the Europa League. This is not what this great club stands for. Big jackpots have long fallen out of their reach, if ever they were a realistic possibility in the first place.

Those early season highs seem to be a long time coming now. Five goals in the opening game at home against Leeds, four goals the next time against Newcastle. Ronaldo’s return home and a warm welcome to his former Real Madrid colleague Varane.

Visitors to Old Trafford were greeted by riot police at their last home game of a season that promised so much, and protesters gathered under a sky of bullets around the statue of the Holy Trinity in honor of Bobby Charlton, Dennis Law and George Best. It was a bleak picture befitting a miserable campaign.

Bruno Fernandes opened the scoring in the early stages when he met Anthony Ilanga’s cross with a fine finishing touch

Fernandes walked away in celebration after breaking the deadlock in United’s last home game of the season

The Portuguese midfielder celebrates in front of the United fans after opening the scoring in the ninth minute

A few of them promised to walk away in the 73rd minute in protest of the club’s owners, but Old Trafford was only half-full when the players embarked on a questionable honor roll at the end.

Some have even given them a chance to say goodbye, like Juan Mata’s start to the season in the Premier League – although interim manager Ralph Rangnick has said there will be no “gifts” in picking his team – and they haven’t disappointed.

Nemanja Matic and Edinson Cavani were also bidding farewell to Old Trafford, and by no means will they be alone.

How many of these players will be back when the Ten Hag turns a new page in August? It’s hard to guess, but mass immigration can run into double digits.

United supporters can only hope that Ronaldo’s wave as he heads into the tunnel means he will be one of them, but there is no guarantee he will want to continue into another season like this one.

It says all about how much he has excelled with this team that the Portuguese star has now scored nine of United’s last 12 goals in the league – eight of them here at Old Trafford.

Raphael Varane (centre) meets Alex Telles corner to score United’s third goal in the match on Monday night

Varane celebrates after scoring his first goal for the Red Devils since joining the club in the summer

That makes her 24 in total for this season. The VAR hit again in the first half last night because he was slightly offside before turning Mata’s cross.

Indeed, Ronaldo was involved in almost every significant move except for the one that led to United’s opening match in the ninth minute.

It was started by Diogo Dalot who hit a pass into the channel to be chased by Anthony Ilanga. The young Swede showed a great acceleration in getting to the ball before it ran out, and crossed Bruno Fernandes to hit it with a powerful shot.

Ronaldo had a worthy opponent in Christian Eriksen. If this is the perfect stage for Dinky to showcase his skills to other clubs – and perhaps even United – he certainly has seized the opportunity.

Eriksen was at the center of Brentford’s best moments, and they could easily have been equal in the second half had Brian Mbiomo converted from an early pass and Evan Toni did not head away from a superb cross pass. David de Gea was twice forced to work from a distance.

The French defender is under attack by his teammates after scoring his first goal of the season in the final at home

But this was one of those nights when Ronaldo wouldn’t have been in office. United’s number 7 jersey had one hopeful appeal, a penalty rejected by referee Chris Kavanagh in the first half when he fell under a Mads Roerslev challenge, but there was no doubt about the second after the hour.

The initial pass came again from Dalot. Ronaldo Rico Henry knocked the ball down and was fouled by the defender in a clumsy recovery challenge. Fernandes missed United’s last penalty at Arsenal, so Ronaldo stepped up and did not fail.

Varane scored his first goal for United when he hit a third kick from Alex Telles’s corner from the knee of Pontus Janssen in the 72nd minute.

By then the farewell was in full swing. Matic and Mata off, Cavani and Phil Jones.

So were the protests. Green and golden smoke drifted over the pitch as a number of fans walked out in the last 17 minutes. They didn’t miss a lot.

When Kavanaugh blew the final whistle and United’s players gathered somewhat frighteningly for that discretionary lap, the club played “Glory, glory, Man United”. Who were they trying to joke?

Ronaldo and his buddies gave their fans something to cheer about at the end of a miserable campaign

Scroll down to see how it all was revealed with Sportsmail’s live runner.