Raheem Sterling embodies the flying start Manchester City have made under Pep Guardiola and his form is the best response to last season’s criticism, which he correctly calls “a bit unfair”.

Sterling was the £49m purchase from Liverpool whom sceptics believed was overpriced and not good enough for City and England. Examine the statistics, though, and the 11 goals he scored for City – plus one for England – were hardly a shabby return for a player who was still only 20 and whose best displays came on the elevated stage of the Champions League.

On Tuesday night Borussia Mönchengladbach are at the Etihad Stadium for the opening group match. City also met the Germans in the same phase a year ago, and in the corresponding fixture Sterling scored twice in a display he described as one of his “best nights in football”. This followed Sterling being the stand-out man, too, when City tore Sevilla apart at the Ramón Sánchez Pizjuán, registering his first European Cup goal in a dazzling offering of attacking menace.

Sterling references that November night when suggesting he was wrongly maligned. “I got a lot of criticism last year which I thought was a bit unfair,” he says. “There were a few games where I made my mark – in the Champions League, where I had never scored. I equalled my best scoring season, with 11. But you need to improve those stats each year. It was a massive learning step for me.”

This campaign has featured assists, two goals, the winning of two penalties – against Sunderland and Steaua Bucharest – and the constant questioning of defenders. He also won the Premier League player of the month award for August.

Sterling is clear, though, that a new confidence is not the prevailing reason. “I wouldn’t say it plays a big part. It is always better to be on a good run and be confident in yourself,” he says. “But at the same time when you hear a bit of unfair criticism sometimes that does put you down a bit. To see people don’t really recognise and see that you are willing to work hard and do the best for your country and club, at times it is a bit frustrating.”

Following the abuse he received for his contribution to England’s 1-1 draw with Russia in the summer’s Euro 2016 opener, Sterling branded himself The Hated One on his Instagram account. Now, he ignores social media. “Yeah, I’ve forgotten about that, it’s simply play football and don’t listen to it, don’t read anything like that,” Sterling says. “Before, you take a stroll and you look at the app on your phone, just being nosey, and you see your name and probably have a little bit of a read. But now I don’t pay it any attention anymore. I simply leave it alone.”

Guardiola has been a long-term admirer of the boy from Wembley and the coach made sure he knew this by telephoning Sterling in the summer.

“Pep coming in was a massive help and for him to be on the phone to me before I’d even met him was a massive boost,” the 21-year-old says. “He said he always liked my football and watched me at Liverpool so to hear stuff like that made me go away and think to basically come back stronger and work harder than ever.

“When I was on holiday I simply said: ‘I need to come back for the season working hard and showing the manager I’m willing to fight for a place in the team’. That’s exactly what I plan to do through the season. A few players are back fit now so it will make it even harder but I’m willing to fight.

“He just makes it simple and tells you how it is, tells you exactly what he wants from you on the pitch and says the rest is down to you. So there is not much of a better feeling than that, for a manager to make the game seem so simple. He is a helping hand, he gives you a lot of encouragement, and as a young player who is always developing and learning, to have someone who has done that at the highest level is a real bonus.”

After that performance against Mönchengladbach, Sterling spoke of wanting to reach Lionel Messi’s level. To do so he will have to be a consistent matchwinner and weigh in with more goals. He is now targeting 15 or more every season. He says: “That’s a realistic target if I’m honest. If you want to be a player at this club those are the numbers you have to be looking at. Those are numbers I should be looking to.”

Guardiola’s embarrassment of riches include Leroy Sané. The 20-year-old impressed in a second-half cameo in Saturday’s 2-1 derby win at Old Trafford. This was the forward’s debut, following injury, and Sterling understands Sané is a rival for a starting berth. “Leroy is a really nice guy but at the same time we play in the same position. Hopefully we can be on the pitch at the same time,” he says. “But it’s not just me, there’s Nolito as well, so that’s the best thing – to have so many players in a position.”

Sterling is playing – and sounding – like a footballer who is up for the challenge of being one of City’s key men.