Alexis Sanchez believes he evolved as a player at Arsenal last season, but felt the team could have achieved more.
The Chile forward is away on international duty with Chile as they host the Copa America.
The 26-year-old, signed in a £30 million deal from Barcelona last summer, was the stand-out player for the Gunners, capping a memorable campaign with a superb goal in the 4-0 FA Cup final win over Aston Villa at Wembley.
However Sanchez feels, with the talent of Arsene Wenger's squad, there remains a sense of what might have been after seeing their title challenge fade despite a strong second half of the campaign, and disappointment in exit from the Champions League to unfancied Monaco.
"It was an OK season, but it was bittersweet. I would have liked to have been in the Champions League final, to have won the Premier League title," Sanchez said in a news conference ahead of Chile's first Copa America match with against Ecuador on Friday.
"I would have liked to be in the Champions League final or to have won the Premier League title. I believe we have a bunch of skilful players so to not achieve more is disappointing."
Sanchez scored 25 goals for the Gunners, and set up many more.
He added: "I had a breakthrough in my football life. Now I switch to the left, I make goals, I pass, I am evolving.
"And if I am put in at centre forward, I will do it in the best way possible and I am fit to play."
Arsenal are expected to strengthen the squad again in the summer, and continue to be linked with a move for Chelsea goalkeeper Petr Cech.
Arsenal midfielder Jack Wilshere, meanwhile, is expected to accept a misconduct charge from the Football Association following his anti-Tottenham chants during the FA Cup victory parade, which could carry a heavy fine or possibly even a suspension.
The 23-year-old has until 6pm on Wednesday to formally respond to the FA, but Press Association Sport understands the player and club are ready to face the sanctions from the governing body's independent disciplinary commission.
Wilshere, who came through the Gunners' youth ranks, took to the microphone to mock the club's fierce rivals as the players celebrated on a stage outside the Emirates Stadium on May 31.
In similar scenes to 12 months ago, Wilshere then proceeded to lead the massed ranks of Arsenal supporters in a chant which included expletives against Spurs, who again finished below their north London neighbours in the Barclays Premier League table.
Wilshere was subsequently reminded about his responsibilities by the club, and also then issued an apology via Twitter for any offence caused.
The FA, though, had issued a written warning to the player for past behaviour and so moved to open a formal disciplinary case.
Following England's goalless draw with the Republic of Ireland on Sunday, Wilshere had looked to put the incident behind him.
"I was a little (disappointed with the charge), but you know that is something the FA are dealing with and my club are dealing with so what will be, will be," he said.
"I have always had that bond with the Arsenal fans since I was young because I came through the club. I grew up at Arsenal and I love the fans, but believe it or not, I have actually got family who are Tottenham fans so it's nothing personal against them, it was just a bit of fun."