Diego Costa has regained his best form for Chelsea this season because he has combined his natural fire with greater discipline, according to former Leicester City midfielder Robbie Savage.
Chelsea head to the King Power Stadium on Saturday five points clear at the top of the Premier League, just 13 months after defeat to Leicester City in last season's corresponding fixture left the Blues languishing in 16th and cost manager Jose Mourinho his job.
Key to their revival has been Costa, who tops the scoring charts with 14 goals in 19 Premier League appearances this season and has also registered five assists as the focal point of Antonio Conte's 3-4-3 system.
Just as impressive as his form has been Costa's discipline, with the 28-year-old picking up one yellow card in the Premier League since September despite being one of the most fouled players in the division. And BT Sport pundit Savage, who made 204 appearances in all competitions during a five-year spell at Leicester City, says this adjustment has been key.
"I'd never want to take that aggression, that desire away from Costa because I'd pay to watch him -- even the Costa of last season, because you don't know what he's going to do," Savage told ESPN FC.
"It's edge-of-the-seat stuff, but he's being more disciplined this year and has focused more on scoring goals. He's been magnificent.
"He had that moment where he rolled his hands [making the substitution sign] at the manager [during a 3-0 win over Leicester City in October], and he looked at the bench and Conte refused to look at him.
"I think from that moment on he realised that with this man it's going to be his way, and he had to be part of that. I think he's embraced it.
"The goal against West Brom showed me everything about Costa -- he chased a lost cause into the corner, rushed [Gareth] McAuley into a mistake, got the ball and smashed it into the top corner.
"That was the winning goal in a game where they were finding it difficult to break West Brom down, and I think that epitomised him. And then in the last minute he was in the left-back position clearing the ball."
This season it is Leicester City rather than Chelsea who are struggling with the burden of being Premier League champions, and Claudio Ranieri's men will also be without Riyad Mahrez and Islam Slimani on Saturday after the pair departed to represent Algeria at the African Nations Cup.
"You could say that Chelsea now are performing at their normal level, as are the Leicester players," Savage added. "Last year Leicester massively overachieved, while Chelsea massively underachieved.
"Last year at the King Power, Mahrez turned [Cesar] Azpilicueta inside out and put one into the top corner and whipped one in for [Jamie] Vardy. I also think Slimani, with his heading ability, might have caused them problems. Leicester being without those two is a huge plus for Chelsea."
Leicester City are 15th in the Premier League after 20 matches, just six points above the bottom three. But Savage insists he is not worried about the possibility of his former club suffering a shock relegation this season.
"I'm confident because they've got performances in them like the one against Manchester City," he added. "I don't think the bottom four or five could put in a performance like that against one of the best teams in the league.
"On their day they can blow teams away like they blew City away for the first half-hour. And they've been in this position before, only two years ago when they stayed up incredibly. So they've got the experience of a relegation fight and showed they've got the character for it. I think Leicester will be fine."