How quickly things change, not just for a single player but for a manager and a club. Chelsea have won three games within a week and scored three goals in a game for the first time since October. The 3-1 win over Leicester on Saturday was the first away day victory since October too.
Most of the club's good feeling ended around then. The goals dried up, results got worse and worse, beyond anything that was expected to come with unprecedented upheaval and turnover. The reward is still small, beating two of the league's bottom five doesn't warrant many awards.
The result against Borussia Dortmund was bigger, that was the night that things appeared to change. Just how much this really matters in the long-run is something that we won't know for a while.
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Nevertheless, it's hard to ignore that whereas it seemed like Graham Potter could do little right in the eyes of Chelsea fans, here he got everything right again. His man-management of Marc Cucurella has been vindicated. Persisting with Kai Havertz has worked and even without Reece James and Thiago Silva the Blues put together a cohesive performance.
Most of the Foxes chances came from Chelsea mistakes, the game of fine margins may have swung against them on another day but Potter is getting the benefit of the doubt right now, and that's still after hitting the post and having two goals ruled out. He would be well justified in saying that his choices paid off though.
Mykhailo Mudryk hadn't started a game for nearly one month and here he was excellent. A close offside call saw his first goal for the club ruled out despite a brilliant celebration in front of the away fans. His movement into the hole on transition saw him acting as a constant threat throughout though, bringing more than just dribbles to the game.
He answered questions that were reasonably being asked before the game. Where does a natural winger fit into a system that gets its width from wingbacks rather than attackers? His touchline hugging, white boots-a-getting style doesn't seem suited to the 3-4-3. Potter threw a spanner in the works.
Mudryk often occupied the central spaces, often coming deep to play passes, especially after Chelsea nicked the ball in midfield and moved forward quickly. He started the move for Felix's disallowed goal and eventually got an assist after knocking the ball back for Mateo Kovacic.
Such was the lack of gametime for the Ukrainian, left on the bench in midweek with Christian Pulisic preferred as an impact substitute, Potter had to address his minutes. "Of course, every player wants to play and it's important that players play to improve, I think that's a fact," Potter explained ahead of the game.
"But at the same time, it's not a straight road, it's not just a play and everything happens in a linear way. Sometimes you have to take a step away. Sometimes you just need a bit of training time. Sometimes you need a breather. So there are a lot of factors.
"Hopefully, he can benefit from the time he's had. And again, it's not easy for him to just arrive in the middle of what was pre-season for him and to come into a new country, new club, new league, and just hit his absolute maximum level. It is regardless of the fee; I know people will look at the fee but it doesn’t change the situation he is in."
It was Mudryk that got the nod over Pulisic and even Noni Madueke in the front three with Raheem Sterling ruled out and that now poses major questions for Pulisic. The American came on in the second half as Potter changed shape to see out the game - another of his tactical decisions that paid off.
He is getting back to fitness after a long lay-off and can't be reasonably expected to play all the minutes, perhaps putting him in here from the start would have been a risk, but Pulisic has been used in a front-three with No10s previously whereas it's a new role for Mudryk. This may well be a telling pick.
The choice that Potter went with, as well as Mudryk being faster and also seen as the future as opposed to Pulisic with an uncertain period coming up, mean that this is a battle that is likely to continue. Chelsea are looking to build a group and Pulisic has been heavily linked with a move away from the club in the summer. There isn't much to say that he is the man they want to pioneer the new age and the fresh attack.
Even though he may want to try and prove a point to Potter it may have to happen in small bursts. It's not optimal for Pulisic and Chelsea would also prefer it if he could impress enough to raise his price on the market or to give the club a serious dilemma over his place in the squad.
Such is the influx of new attackers it's hard to see the USMNT remaining at Stamford Bridge beyond this campaign and if he isn't playing in a role he has more experience in then what comes next really is uncertain.
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