Seagulls boss Potter said: "I thought he linked the game well, it was his debut in the Premier League and I thought he did what we asked him to do.

"He got in the box for two goals – one disallowed – and had another good chance as well.

"It was a good, solid debut for him and, like the team, he'll get better over time."

West Ham had lost both their previous Premier League visits to Sussex and should have lost this one, too, with Brighton dominant throughout.

Trossard was celebrating a debut goal in the 27th minute until VAR ruled it out with Dan Burn, who had crossed for the Belgian to volley home, caught offside in the build-up.

It was the correct decision but the delay was bordering on the ridiculous. Both teams had lined up ready for the restart by the time on-field referee Anthony Taylor got word in his ear that VAR Darren Bond had spotted the infringement.

"They're there for that, is it offside or isn't it?" added Potter. "It doesn't matter if it's a millimetre or a centimetre, it's offside.

"It's not very pleasant, it changes the atmosphere in the stadium from euphoria to disappointment.

"I'm sure it will happen again, it's something we need to deal with. It's a challenge.

"It's an emotional game, and we probably deserved that goal. In an ideal world it would happen quicker, but you want them to be correct as well."

West Ham had not had a shot on target until Manuel Lanzini sent Hernandez through on goal to fire them ahead just after the hour.

The lead lasted just three minutes, Trossard pouncing on Issa Diop's poor clearance to beat Lukasz Fabianski.

Both sides had chances to win it and West Ham manager Manuel Pellegrini claimed a draw was "a fair result".

It was at least a vast improvement on last week's 5-0 defeat at home to Manchester City.

Pellegrini added: "It was important not to lose a second game in a row. I made changes because I wasn't happy with last week.

"We know Hernandez can score and we have a lot of players that were coming back from injury last season."

Pellegrini said he expects record signing Sebastien Haller and Brazilian winger Felipe Anderson, both missing through injury, will be back next week.