Romelu Lukaku's game-changing impact at Villa made Thomas Tuchel take a fitness risk.
The forward came off the bench at the break and the visitors went on to win.
He scored his first goal in the league since September against Villa and then won a penalty for Jorginho to score.
It was the second spot kick for the Italy player, who had already scored from it in the first half.
It wasn't fair to force him back into action for a full half, as he was delighted with his impact, while Tuchel said it was not necessary.
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The Premier League is the only league in Europe that does not allow five substitutions and winter breaks, and Thomas Tuchel was frustrated by it.
It's not right today. He had a good performance and was helpful, but it's not fair. Even if he wants it, he's not ready for it.
We have been in bed for 10 days with the flu. We don't know what will happen after I didn't play at Villa Park. We don't know what the impact is, we just put the players in. He made a big difference today. I'm very impressed with the guys, but I'm worried.
He is very important. Romelu is a key player. He started for us in October, not because of quality, but because we were better without him. He is unlucky to get injured.
He caught Covid when he was struggling to come back. It was more than the fitness and medical department recommended for him, but we thought we could be more offensive.
Tuchel admitted that his celebrations are a bit more subdued because of his concerns about his players' health, having lost N'Golo Kante and Thiago Silva to injury.
Romelu Lukaku is in front.
He said that he was concerned about the health and safety of the players and that's why he wasn't excited.
Normally, you could push them and catch huge momentum, but we are only checking on a daily basis who can be pushed.
Tuchel spoke to Sky Sports before his press conference and expressed his frustration with the officials.
He said that he was impressed with his players but concerned.
We may have made a mistake by letting players play after corona and one or two training sessions. They made us play and so we play.
This is not the right way. The people at the green table are making decisions. This is how it is.
The title race is back to normal.
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There are highlights from the game between the two teams in the Premier League.
Jamie Redknapp says that the win over Villa has brought the title race back into focus.
The Belgian, who has not started any of the last 11 games due to injury and illness, was sent on at half-time. He headed them in front with his first league goal. He capped a great performance with a driving run to win a late penalty and finish off a vital three points.
With Manchester City winning earlier on Boxing Day, the defending champion couldn't afford another slip-up and they are now level on points with second-placedLiverpool and six points behind the defending champion.
It's still a challenge for the Blues to return to the top of the table after recent disappointing results, when they have failed to convert their dominance into goals. They are right in the mix with the return of Lukaku, according to Redknapp.
The Sky Sports pundit said that Lukaku had single-handedly gotten his team back in the title race.
They needed a spark and that's exactly what he brought. In the first half, the manager was confused as to what to do.
Jorginho scored his penalty.
The obvious thing was to bring him on, because they struggled so much with Christian in the first half.
The two people who had bullied Pulisic wereTyrone Mings and Ezri Konsa. It was easy for them. They knew they were going to be in a fight for the next 45 minutes after Mings crashed into his goalkeeper. That set the pace.
He made a huge difference when he came on. He said that he was confident. Everything started to move.
He gives them something completely different and you can play from behind or deep.
When they have their best players on the pitch, like N'Golo Kante and Romelu Lukaku, they look a lot better. They're right in the title race.
I think City andLiverpool are the best teams at the moment, but I think it's important for them to hope that things don't go their way.
"But if they win it, he is going to play a big part."
We are the hunters.
After just 11 minutes after coming on, Lukaku scored.
The early part of the season was good for the Blues, but now they have to catch up to City. They will relish their role ashunters.
He mentioned his frustration at being stuck on the sideline when he spoke to Sky Sports after the win at Villa.
He said that it had been difficult as every player wanted to play.
The manager has reasons, but I kept working hard. It was good for us to win today, and I am happy with my performance.
We have to chase every game and treat every game like a final.
The return of Lukaku gives hope.
Romelu Lukaku scored his second-half goal.
Sky Sports' Peter Smith.
"Lukaku's impact at Villa was a reminder of his debut against Arsenal, bringing quality finishing to an all-too-often wasteful Chelsea attack, and pace and power to the frontline."
His goal was his first in the league since September when he started for the Blues.
In January, they will play Manchester City and Manchester Reds again, and they dropped points to both of those teams during that run. It will be the most important moment in the title challenge.
"With Lukaku fit and finding his form before those blockbusters, we can believe again."
The Slick City set ominous pace.
