Chelsea boss Mauricio Pochettino believes there is much more to come from Armando Broja

The 22-year-old started in place of Nicolas Jackson, who is away at the Africa Cup of Nations, and netted his team's opening goal early in the second half at Stamford Bridge.

Preston had done a fine job in the first period of containing Chelsea, who lacked cutting edge to go with their domination of the ball, but Broja's strike was the first of three in an 11-minute spell in the second half.

Will Keane was hounded off the ball inside his own box by Mykhailo Mudryk, who laid it back for Malo Gusto to cross and Broja headed in.

Thiago Silva then nodded in a second before Raheem Sterling quickly lashed a free-kick beyond goalkeeper Freddie Woodman.

Enzo Fernandez knocked in a fourth near the end as the gulf to Ryan Lowe's side – 14th in the Championship – finally showed.

Pochettino praised the contribution of Broja, who returned to fitness in September after nine months out with an ACL injury, and hinted there is more to come from the Albanian striker.

"It was really important for him," he said. "I need to be honest, he needs to use this type of game to score and to feel the net and to improve. Improve not only in his fitness but his body language also. He needs to step up and to go forward and to move. He needs to smile more and be more positive.

"The potential is amazing. We're talking about one of the young strikers in England and in Europe with most potential. But the problem now is he needs to push himself, and we're going to try to help him to realise that never it is enough.

"He was nearly one year away (injured) and of course now he needs time. It's not easy for him to perform and to be at the level we expect. Our expectation is massive and we really believe in him. We're going to push him to improve every day.

"I said to him smile. Always we joke about how he needs to smile, to laugh, to put inside himself more good energy and be more happy, a happy boy."

Preston boss Lowe reflected on a game that got away from his side in the second half after a promising start.

"The three goals in (11) minutes really hurt us," he said. "I think for large parts of that game, before the 58th minute when they scored, we were fantastic.

"It is disappointing to lose and I don't think the result reflects the performance, but the fact is they have good quality players who can put the ball in the back of the net.

"I thought our lads were excellent. They gave it their all and that's the biggest thing I am pleased about."

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