Since dropping back down to the Championship in January on loan, the striker has looked like a new man. He's been crucial to helping the Cottagers to extend their unbeaten run to 22 games and they are guaranteed at least a play-off position with two games to go.
After scoring just four goals in the Championship last season, Mitrovic has netted 11 times in 15 appearances for Fulham. But what has changed for the enigmatic 23-year-old?
It's no secret that Newcastle manager Rafa Benitez and Mitrovic didn’t get on during his time at Newcastle, with the Magpies boss preferring the likes of Dwight Gayle, Joselu and Ayoze Perez in attack. Before joining Slavisa Jokanovic's side on loan, Mitrovic had made just six substitute appearances in the Premier League this season.
Mitrovic was sent off twice in his debut season at Newcastle and his unpredictable temperament drew criticism in the past, with Benitez unhappy with the forward after a 6-0 win against Preston last season when he was booked for his celebration after scoring his second goal of the game. He was then involved in an altercation with Matt Ritchie about who was going to take a penalty when Mitrovic was on for a hat-trick.
Rather than praise Mitrovic for his brace, Benitez reprimanded the striker for his behaviour, saying: "It's a silly thing to do and you don't need to do it.
"They need to know that arguing to take a penalty when we have already decided on a penalty taker also makes no sense."
But Fulham boss Jokanovic has enjoyed a better relationship with Mitrovic than Benitez did, with the pair both having previously been at Partizan Belgrade.
Jokanovic seems to have curbed that temper in Mitrovic, with the striker showing a new-found ability not to react after he was elbowed in the head against QPR last month.
A difference in playing styles has also enabled Mitrovic to shine, with the £14.5 million man critical of Newcastle's system, saying that he prefers the attacking set-up at Craven Cottage.
“This season, this team, we always try to score more goals than the opponent,” he said. “Newcastle was more tactically [set up].
“We didn’t play as much attacking football as I play now.”
Mitrovic has also been perfect for Fulham’s system as Jokanovic’s side love to play the ball wide to utilise their pacy wingers and full-backs, and then cross low into the box.
Earlier in the season, Fulham were struggling for goals without someone in Mitrovic’s mould, and this was particularly evident in a 1-1 draw with Derby at home in November when Ryan Fredericks and Ryan Sessegnon repeatedly played balls across the six-yard box with nobody there to finish.
A lack of a plan B was also a criticism of Fulham earlier in the season as their possession style was unravelled by teams who pressed high up the pitch. Burton Albion and Bristol City figured this out when beating the Whites in September and October respectively.
But, with Mitrovic up top, Fulham now have a focal point for their attacks, whereas goals were spread throughout the squad before his arrival. He has allowed Fulham to play a different style when they’ve needed as well, especially when a change of approach against Preston saw Mitrovic score twice in a 2-1 win.
Fulham legend Barry Hayles was full of praise for the impact Mitrovic has made at Craven Cottage, telling Goal: “Mitrovic has been a great signing, his ability to hold up the ball and bring the team up the field has been invaluable and his goalscoring just adds to how well the team is performing at the moment.”
Last year, Mitrovic was not getting much time on the pitch as Newcastle breezed towards promotion from the Championship, finishing nine points clear of third place.
Fast forward 12 months, however, and Mitrovic has a point to prove. He seems desperate to show everyone that Benitez was wrong to send him out on loan and he has another promotion firmly in his sights.
He is playing regular football in a system he likes and under a manager he respects. Mitrovic, Jokanovic and Fulham will now hope to finish the job and join Newcastle in the Premier League.