Nottingham Forest have no time to celebrate reaching the Europa League semi-finals amid their battle to remain in the Premier League, says head coach Vitor Pereira.

Following a 1-1 first-leg draw in Portugal last week, Forest inched into the last four with a nervy 1-0 victory over Pereira's former club Porto at the City Ground.

Morgan Gibbs-White's deflected strike proved decisive after Porto had Jan Bednarek sent off in the eighth minute, as Forest reached their first European semi-final since the 1983-84 UEFA Cup.

An all-English showdown with Aston Villa awaits them in the last four, but Pereira's mind is already on another game – Sunday's Premier League meeting with Burnley.

Forest are 16th in the table and the Opta supercomputer assigns them a 9.5% chance of relegation, with Burnley and Wolves both at 100%, Tottenham at 50.8% and West Ham at 38%.

Asked by TNT Sports how he would balance a relegation dogfight with a European semi-final, Pereira said: "It starts now in the dressing room. After this game, we will start to speak about the next game. 

"We don't have time to celebrate. It's time to recover and come back again, to be mentally strong. I prefer to come with a win – the motivation is different. 

"It's just Burnley in my head at the moment! It's too much to think Villa too. I will think about it after Burnley. It will be a tough game; we need our supporters again. We need to go again as a family."

Bednarek's sending off, which came for a high challenge on Chris Wood near the halfway line, was the earliest in any Europa League knockout-stage match since Raul Meireles for Fenerbahce versus BATE Borisov in February 2013 (fourth minute).

"We got fortunate with them going down to 10 men, we knew it would be difficult. Incredible win and we go onto the semi-finals," Gibbs-White said. 

"It was an incredible night, one of the best nights I've had at the City Ground, thanks to the fans and everyone that made it happen. 

"We said early on that we'd take this competition full-on, and we deservedly got the win today. Now we rest and go into the league."

Gibbs-White celebrated his goal by holding up a shirt bearing Elliot Anderson's name, with his fellow midfielder absent for Thursday's game following the death of his mother.

"It's a really emotional night," Gibbs-White said. "It's a big shame, he's an incredible kid and no one deserves this, but we're all with him."