With the Premier League back, it goes without saying that dodgy officiating has also returned.
It is a new-look group of referees for the new campaign, too, with Mike Dean, Jonathan Moss, Martin Atkinson and Kevin Friend having all retired over the summer.
Tierney is now in place as one of the most high-profile officials, and the 41-year-old from Greater Manchester will be in charge for Liverpool’s first home game of the season.
Martinez brought Welbeck down while the Seagulls were 2-0 up, but should have been given an opportunity to make it 3-0 only to see their protests overruled, while a later decision saw Scott McTominay lucky to avoid a second yellow card.
It is not the first time Tierney has courted controversy, of course, as it is, in a way, the nature of the job.
Back in December, he was roundly criticised for his officiating of Liverpool’s 2-2 draw at Tottenham, namely in not sending off Harry Kane before showing Andy Robertson a red card for a similar challenge and not awarding a penalty for Diogo Jota.
In fact, in his explanation of the incident, Tierney effectively accused Jota of drawing the foul – ignoring, of course, that the operative word was ‘foul’.