On Sunday Raheem Sterling has the chance he craves: to be a match-winner in a major final, when he steps out for Manchester City against Liverpool in the Capital One Cup showpiece. If Sterling is pivotal to his new club winning a first trophy since the 2014 Premier League, a season of promise pocked by inconsistency becomes one of undoubted success, after his controversial £49m transfer from City’s Wembley opponents.

As Manuel Pellegrini, his manager, says: “If we win a couple of titles and Raheem has an important performance it will be a good season for him. He has done good things, bad things and was very important the other day [against Dynamo Kyiv]. He continues to improve and give a lot of things to our squad. He has a lot of speed, good technique, goals – that’s why we bought him. I’m sure he can be a very successful player but it will depend on the way he improves.”

Sterling would be vindicated, too, by a City victory on Sunday. The irony is this is precisely the kind of occasion Sterling felt he could experience only by leaving Anfield. To see Liverpool barring his way to a first piece of silverware illustrates the vagaries of sport, though the driven 21-year-old will not care.

Pellegrini says: “For every player it is never comfortable to play against an old team. Everyone has links, friends inside the club. But he is a professional player. He came here to win titles. I’m sure he will have a very good performance.

“I don’t think he has anything to prove. I hope he will be focused on having a good performance and not thinking about the boos he receives during the game or what happened in the past.”

Sterling possesses his own brand of Roadrunner speed, jinking turns and an ability to create and score goals, though the latter is a work in progress. He has a further attribute: mental strength. The hue and cry over the departure from Merseyside included accusations of being a mercenary and of having no respect for one of English football’s institutions. The truth, he says, was far tamer yet there were still many who wanted Sterling to fall foul of hubris and fail.

He has not. There have been 10 goals for City and Sterling should score the two required to beat his best for Liverpool. He claimed a maiden league hat-trick – in October’s 5-1 win over Bournemouth – and his pass accuracy has increased from last year’s 81.11% to 85.6%

But it is in the Champions League where Sterling has shone, on the two occasions a performance was required. As Pellegrini notes, in Wednesday evening’s 3-1 victory in Kiev in the last-16 opening leg Sterling broke the tie open by creating the first two goals. He claimed the corner that led to Sergio Agüero’s strike and then, after his football brain found him space to receive the Argentinian’s back‑heel, a cross removed the defence, and Silva could not miss.

The display complemented Sterling winning City their crucial group match, again away from the comfort of home, at Sevilla, which sealed qualification two matches early. On a warm November night at the Estadio Ramón Sánchez Pizjuán, Sterling tore Unai Emery’s side open, beginning the scoring and creating Fernandinho’s second in another impressive 3-1 win.

Sterling also scored two in the 4-2 defeat of Borussia Mönchengladbach at the Etihad Stadium on 8 December but there is surely more to come. The holy grail is consistency. Kevin De Bruyne, another summer arrival, instantly delivered with 12 goals and 12 assists before suffering a knee injury in January.

Sterling is yet to perform week in week out. He has not scored in the league in 2016, his last goal coming on 30 January in a 4-0 FA Cup victory at Aston Villa. He has two league assists compared with last season’s seven, and with 12 games remaining has a challenge to better that 2014-15 total.

Do not count against him doing so. Sterling may be young but his CV shows a high volume of football and an ability to seize opportunity. A debut 2011-12 season that numbered three appearances and no goals was followed by 37 games and two finishes in 2012‑13, 44 and 10 in 2013-14, and 61 and 12 (including one for England) last year. He was one of the few players to feature in all England’s games at the Brazil World Cup, where for the opener against Italy Roy Hodgson decided the captain, Wayne Rooney, should be moved left to accommodate Sterling in the key No10 berth, and he proved the stand-out player.

On Sunday Sterling, who is from Wembley, fulfils a dream of playing a cup final at his local stadium. He hopes to achieve another and win a trophy. Whatever Sterling says publicly, it would surely be all the sweeter for him to do that against Liverpool.