Chelsea coach Thomas Tuchel praised his players for remaining focused amid the uncertainty about the club's future after they progressed Wednesday to the Champions League quarter-finals, where he said they would be "the team nobody wants to play".

The reigning European champions came from behind to beat Lille 2-1 in northern France and win their last-16 tie 4-1 on aggregate with Christian Pulisic and captain Cesar Azpilicueta scoring their goals.

The victory came on the same day it emerged that the Ricketts family, owners of Major League Baseball team the Chicago Cubs, were leading a consortium looking to buy the club while British athletics great Sebastian Coe announced his involvement in a rival takeover bid.

Reeling from the impact of UK government sanctions imposed on their Russian billionaire owner Roman Abramovich, it was also reported on Wednesday by Sky Sports that EU sanctions mean Chelsea cannot sell tickets for their next Champions League home ties.

If confirmed that would mean Chelsea playing behind closed doors in Europe at Stamford Bridge.

"Thanks for ruining my evening," Tuchel said when that was put to him as he spoke to reporters at the Stade Pierre-Mauroy.

"Can we speak about it when it's confirmed? Let's see. Today I'm happy we are in the last eight."

Chelsea have now played five games since Abramovich put the club up for sale on March 2 and won them all.

Since losing 1-0 at Manchester City in mid-January, Tuchel's team have lost just once, on penalties to Liverpool in the League Cup final.

"Chelsea is so clear what it demands from every employee and from every player -- play your role to the limit, live up to it and take responsibility," Tuchel said when asked how he and his team managed to maintain their concentration amid all the turmoil.

"This is what Chelsea is about and that sharpens your mentality and brings out the best in you because it is normal to do it on a daily basis and because this mentality has been installed over years and years.

Thomas Tuchel celebrates with his players after Chelsea beat Lille to reach the Champions League quarter-finals
Thomas Tuchel celebrates with his players after Chelsea beat Lille to reach the Champions League quarter-finals AFP / FRANCK FIFE

"That is why it is possible that we can stay focused and produce results, as we do now when things are uncertain and unstable around us."

Tuchel admitted that Chelsea had got it badly wrong in putting in a request for their next game, an FA Cup quarter-final away to Middlesbrough on Saturday, to be played behind closed doors in the interests of fairness and "sporting integrity".

The club, who are only allowed to operate under a special licence, cannot sell tickets, with only existing ticket-holders allowed to attend matches.

"Let me put it like this -- we love to play in front of spectators and I don't think spectators of our opponents should suffer from the consequences," said the German.

"It was not the best idea. We love to play in front of spectators and I am happy it was turned down."

Despite all the turbulence, Tuchel's team will be in Friday's draw for the Champions League quarter-finals along with fellow Premier League sides Liverpool and Manchester City as well as Real Madrid, Atletico Madrid, Villarreal, Bayern Munich and Benfica.

"I want us to be the team nobody wants to play," Tuchel said.

"It's a big step to do it again and again and that is why we fight for top-four places in maybe the toughest league in the world and we fight now again in the top eight teams.

"This brings out the very best in us."