Valencia forward Goncalo Guedes is nicknamed Ducati by his team-mates for his effortless yet explosive motorbike-like acceleration, but has often fluctuated between scorching hot and freezing cold.

With six goals and three assists in his past 10 games, the 22-year-old is an all-or-nothing kind of player - equally capable of delivering match-winning heroics or leaving you wondering if he's even on the pitch.

Unfortunately for Valencia, last Thursday's Europa League semi-final first-leg defeat at Arsenal saw one of his too-frequent underwhelming performances; the Portuguese made little impact and was substituted after 70 minutes.

Signed by Arsenal boss Unai Emery for Paris St-Germain two years ago, Guedes was largely overlooked while in France.

So could the forward, who is said to epitomise the "new Valencia", send a message to his former boss and help overturn a 3-1 scoreline against Arsenal on Thursday?

A precocious youngster - but did Emery show faith?

It's easy to say with hindsight, but from an early age, Goncalo Manuel Ganchinho Guedes looked destined for stardom.

Guedes made his Benfica debut at the age of just 17

After being given his first football at the age of four by his parents, young Goncalo rapidly developed his talents and was invited to join the youth system of Portuguese giants Benfica at eight. He wasted no time in making an impact, scoring all the goals in a 5-0 win on his debut.

Benfica's base in Lisbon is a fair distance from his small home town of Benavente, but Guedes and his father committed themselves to undertaking the 80-mile round trip several times a week, and the young player's coaches were impressed by his calm but confident manner, along with his commitment to honing his skills.

"He was always a real brat, totally extroverted, but he was never a rude kid," Luis Nascimento, who coached Guedes in the Benfica youth team, told Bleacher Report.

"He was very polite, but not an easy kid to handle. He was very bold on and off the pitch. He never feared his opponents. He was never afraid of making mistakes. He was ambitious."

Guedes' dazzling displays in junior football caught the eye of Benfica first-team boss Jorge Jesus, who gave the rising star his senior debut in October 2014, aged just 17.

The following year delivered his first Champions League goal in a 2-1 victory at Atletico Madrid, and in November 2015 he became the youngest player to represent Portugal since Cristiano Ronaldo.

With a move away from Lisbon inevitable, it seemed Guedes would swap the Estadio da Luz for Old Trafford, as Manchester United led the charge for his signature.

Instead, the race was won by Paris St-Germain, who had been among his victims during Benfica's Uefa Youth League campaign in 2014. They bought him for 30m euros in January 2017, shortly after his 20th birthday.

The high-profile transfer looked like his latest step towards superstardom, but the Parisian adventure put an abrupt halt to Guedes' progress.

He played less than five hours of football over the remainder of the 2016-17 campaign, starting just two games as manager Emery consistently overlooked him.

"It was a bit odd, considering PSG's then-sporting director Patrick Kluivert really wanted him and when he came on he looked assured and confident," said Jerome Pugmire, a French football journalist based in Paris with the Associated Press.

"He was not afraid to take defenders on and his strong running caused problems, even with so little playing time.

"He was considered a young talent with a bright future who wasn't really given a proper chance to shine.

"This is certainly what Kluivert thought, saying that Guedes needed a coach who believed in him, thereby suggesting Emery didn't show enough faith in him."

Valencia's 'revolutionary'

Guedes slipped further down PSG's pecking order in the summer of 2017 with the arrival of Neymar and Kylian Mbappe, and he was allowed to leave barely six months after arriving.

Thanks to the close connection between Valencia owner Peter Lim and Guedes' agent Jorge Mendes, his next stop was Valencia on a season-long loan.

Guedes immediately made up for lost time at Mestalla Stadium, with three goals and five assists in his first seven games for the club. He showed fast and strong running, skilful ball control, and a power-packed right-footed strike.

An article in Marca gushed that he was "revolutionising" the team, and a feature on TV review show El Dia Despues called him the "one who makes the difference" who epitomised "the new Valencia".

His form dipped towards the end of the season, with just one goal after mid-January, but in the summer Valencia were still prepared to invest 40m euros to make Guedes the club's record signing.

"His impact last season turned him into one of the team's most beloved players, and he consolidated those feelings by standing his ground and pressuring PSG to accept Valencia's offer last summer," said Paco Polit, a Valencian journalist.

"He's very humble, down to earth and just enjoys chilling around the city. In fact, the comfortable lifestyle in the city helped him settle and was one of his main draws to return."

Guedes was back in Valencia, and this time for good. But then things didn't go quite to plan.

Another step back... and another explosion

After an outstanding 2017-18 campaign, Valencia won only three of their first 16 league games this season and failed to progress from their Champions League group.

Guedes, in particular, was having a difficult time, recording no goals or assists in the first six months of the season, picking up a hernia injury and then being whistled by some disgruntled Valencia fans for the first time when he was substituted against Krasnodar in the Europa League last 16.

Yet just as Guedes appeared to have lost his way, he produced a huge moment by coolly netting a 93rd-minute tie-winning goal in the return leg at Krasnodar. Since then, he has not looked back.

He scored twice in the Europa League quarter-final win at local rivals Villarreal, netted a brilliant opener in a home league win over Real Madrid and struck both goals in a league win at Real Betis.

Polit, who describes the forward's inconsistency as "quite annoying", notes: "At his best, Guedes is hands down a world-class player. But three months out of a whole season is not enough."

On Thursday, this gifted forward will have the chance to cement his return to form in a crucial contest, and his importance was shown when manager Marcelino withdrew him, along with skipper Dani Parejo, at half-time during Sunday's thumping 6-2 La Liga win at Huesca.

With his energy preserved for Thursday, Guedes is in form and ready to deliver - if he hits top form, do not be surprised if Arsenal find themselves outgunned.