For Ross Barkley the relief was obvious, and so was the promise. The most frustrating season of his adult career was behind him at last.

On the pitch, last season could hardly have gone much worse. He made just four brief appearances, only two starts, never completing 90 minutes. They all came after his £15million move from Everton to Chelsea, but he could never get fully fit enough to justify his presence at Stamford Bridge.

This year is already is already different. Barkley has been a regular for Maurizio Sarri in pre-season and on Sunday he played 90 minutes against Manchester City in the Community Shield. It was his first full competitive game since May 2017, when he was still at Everton and Ronald Koeman was trying to convince him to sign a new contract.

Now he has got this far, Barkley can finally look forward to making an impression on the new season. “I played 90 minutes for the first time for a long time,” he said after the Community Shield at Wembley on Sunday. “I felt really good out there and game by game I'm going to be feeling much stronger going into the season.”

Community Shield: Chelsea vs Manchester City player ratings Show all 22 1 /22 Community Shield: Chelsea vs Manchester City player ratings Community Shield: Chelsea vs Manchester City player ratings Willy Caballero - 8/10 Unlikely to feature too much this season barring injury, but had an improved second half as he denied Aguero and Jesus on several occasions. REUTERS Community Shield: Chelsea vs Manchester City player ratings Cesar Azpilicueta - 6/10 Had a fairly good game considering the shaky defence next to him, and as has happened before he plugs away doing the dirty work and giving his all for his team. AFP/Getty Images Community Shield: Chelsea vs Manchester City player ratings Antonio Rudiger - 5/10 Not at fault for Aguero’s goals, but the first goal went through his legs, and he combined less than convincingly with David Luiz. AP Community Shield: Chelsea vs Manchester City player ratings David Luiz - 5/10 Despite getting to the business end of his career, the same old problems plague Luiz. He has all the skill and quality to make a very accomplished centre back but can’t quite get it all together. Action Images via Reuters Community Shield: Chelsea vs Manchester City player ratings Marcos Alonso - 6/10 Had an average game in a defence that looked leaky at best. Will likely improve during the season and can nick a goal or two on his day. Getty Images Community Shield: Chelsea vs Manchester City player ratings Cesc Fabregas - 6/10 Failed to thread many of his trademark balls forward and looked off the pace, but with a poor defence behind him, had little to feed off. PA Community Shield: Chelsea vs Manchester City player ratings Jorginho - 6/10 Understandably his touch and some of his play was far from perfect as he adapts to the English game, but it’s clear to see Sarri sees him as a key figure for Chelsea to play through this season. Getty Community Shield: Chelsea vs Manchester City player ratings Ross Barkley - 6/10 Showed some signs of his promise before his move to Chelsea, and will look to build on this going into the new season. AP Community Shield: Chelsea vs Manchester City player ratings Pedro - 6/10 Another of the Chelsea players in attack to have very little to feed off, had a half chance in the second period but didn’t get much help from his teammates as he tried to create chances. Getty Images Community Shield: Chelsea vs Manchester City player ratings Alvaro Morata - 5/10 Had little service, and looked short of confidence when he did get the ball. His big test will be the Premier League as he looks to find some form and more importantly get on the scoresheet. REUTERS Community Shield: Chelsea vs Manchester City player ratings Callum Hudson-Odoi - 7/10 A bright spark for Chelsea, and will certainly give Sarri something to think about in the season ahead. Coped well against the talent and speed of Kyle Walker. AFP/Getty Images Community Shield: Chelsea vs Manchester City player ratings Claudio Bravo - 7/10 A bizarre moment where the ball bounced over him aside, it was a good performance from Bravo with his usual accurate distribution. Getty Images Community Shield: Chelsea vs Manchester City player ratings Kyle Walker - 7/10 Dealt well with Callum Hudson-Odoi who was one of the better players in a poor Chelsea side. One to return early from the World Cup, and looked almost back to his best. Getty Community Shield: Chelsea vs Manchester City player ratings John Stones - 7/10 Another assured performance from a player building on a successful World Cup. Even found himself in defensive midfield as the game went on, and will hope to build on this into the season. Action Images via Reuters Community Shield: Chelsea vs Manchester City player ratings Aymeric Laporte - 7/10 A new signing last season, Laporte was seen as one of the best defenders in the world and looked solid here despite never really being tested by a toothless Chelsea frontline. AFP/Getty Images Community Shield: Chelsea vs Manchester City player ratings Phil Foden - 8/10 One of the few that will have seen the Community Shield as a huge game. He left the field to a standing ovation and was impressive throughout, picking up an assist for Aguero’s opener. Action Images via Reuters Community Shield: Chelsea vs Manchester City player ratings Benjamin Mendy - 7/10 Almost a new signing for City after his long injury last season, and showed some glimpses of his form at Monaco as he raced up and down the left flank. AFP/Getty Images Community Shield: Chelsea vs Manchester City player ratings Fernandinho - 7/10 The few times Chelsea managed to string passes together, Fernandinho was there to break up play. He will face much stiffer tests during the Premier League season. REUTERS Community Shield: Chelsea vs Manchester City player ratings Bernardo Silva - 8/10 One of the best in an impressive City team, and filled in for David Silva seamlessly. His attacking runs easily carved through the Chelsea midfield and defence. AFP/Getty Images Community Shield: Chelsea vs Manchester City player ratings Riyad Mahrez - 7/10 Guilty of sometimes taking too many touches, but as always a bright spark, and someone who will add to City’s squad this season. Getty Images Community Shield: Chelsea vs Manchester City player ratings Sergio Aguero - 9/10 Got his 200th and 201st goals for City and was clinical as he has been so many times in a City shirt. Given far too much space though by a poor Chelsea defence. REUTERS Community Shield: Chelsea vs Manchester City player ratings Leroy Sane - 7/10 A good performance, but plenty more left to give from Sane, who will likely be up against Mahrez for a place in the starting XI this season. AFP/Getty Images

Injury setbacks are nothing new to Barkley. He missed a whole year at the age of 16 when he broke his leg playing for England Under-19s, slowing down his development at Everton under David Moyes. Barkley insisted that he “always responds well to them”, but admitted how hard it was as a lifelong footballer to get used to a long spell away from the game.

“You miss the feeling on the pitch, you miss hitting the back of the net, you miss the winning feeling,” Barkley described. “That's what drives me. I just miss being out on the grass. As a young lad it's been your dream to play football and you get injuries and you've got to respond well to them and work really hard, because it's your dream to be on the pitch.”

But since Sarri arrived at Chelsea last month Barkley has been handed the chance to get back on the pitch again. Sarri has said that he likes Barkley, because for his high-intensity aggressive pressing football he needs footballers with all of the obvious attributes that Barkley has. Seeing Barkley charging around at Wembley on Sunday he looked like player who Sarri might want to help set the tempo in his Chelsea side this year, and with the energy to break forward in those high-speed interchanges that characterised Sarri’s brilliant Napoli side.

The Premier League season has not even started yet but Barkley has enjoyed what he has seen of Sarri so far and is excited about putting his football ideas into practice on the pitch.

Sarri is trying to install his system at Chelsea (AFP/Getty Images)

“We're still learning and getting to know the new manager's way of playing,” Barkley said. “I'll play any style of play for any manager, but it is my type of style. He's an attacking manager, he wants exciting football, to be high up the pitch pressing, scoring goals and being exciting, scoring a lot of goals, team performances all round.”

Barkley has been watching footage of Napoli from last season, to see how their attacking players move and combine on the pitch, and so he can get a head-start in learning what he has to do at Chelsea. Barkley failed to make any real impression under Conte, but Sarri could be the man to provide the structure he has desperately lacked in his career. Barkley is still young and raw enough to be moulded by Sarri, which is a thrilling prospect for English football.

Barkley could yet thrive under the Italian (AP)

“I've watched clips (of Napoli) just to see the way they played, out of possession and in possession,” Barkley said. “I've seen how they played last season, and against Manchester City last season in the Champions League. They were a really exciting team, one-twos all over the pitch, one and two-touch football. Goals from all around the pitch. It was exciting football, and they were unfortunate not to win the league last season.”