It was an idea briefly explored, a conversation that soon died a death, but there was a moment last summer when Chelsea were talking about including Nicolas Jackson as part of a deal that would have taken Newcastle’s Alexander Isak in the opposite direction.

There was much admiration for Isak at Chelsea. They were keen to add a top striker to Enzo Maresca’s squad and the Sweden international was prominent in their thoughts. Was a deal possible? Newcastle had concerns regarding profitability and sustainability regulations, although they were never going to sell Isak on the cheap. The only way to make it work was to follow the route favoured by a lot of Premier League clubs: alter the fee by throwing in players as part of the bargain.

The talks never went anywhere, though, and perhaps that is just as well for Chelsea given that Jackson is in flying form before Newcastle visit on Sunday afternoon. The Senegal international scored his fifth goal of the season in last weekend’s unfortunate defeat by Liverpool and is doing much to silence suggestions that the only thing missing from Maresca’s squad, other than a reliable goalkeeper, is a world-class No 9.

How, pundits have wondered, can it be that Chelsea have spent so much without ensuring that they had a lethal finisher leading the line? How could the co-sporting directors, Paul Winstanley and Laurence Stewart, be so shortsighted? How could the owners not have moved heaven and earth to sign Victor Osimhen from Napoli?

The irony is that Chelsea are being rewarded for gambling on Jackson in the summer of 2023. They have overspent on some signings, but Jackson is beginning to look like a bargain. He joined from Villarreal for only £31.8m – Rasmus Højlund cost Manchester United £72m – and despite occasionally being a target of derision during his debut season in England, is clearly moving in the right direction under Maresca’s guidance.

It is true that Isak is a silkier mover than Jackson, a more assured and versatile finisher, colder and more varied in front of goal. Jackson can look rushed, erratic and unsure of himself. He was pilloried after missing a succession of glaring chances when Chelsea lost their FA Cup semi-final to Manchester City last season.

There was also the ridiculousness of Jackson having to serve a one-match ban after repeatedly getting booked for dissent at the start of last season. Mauricio Pochettino, Maresca’s predecessor, could only despair at the inexperience and naivety. Internally, though, there was patience.

It did not help that Jackson had struck up a good understanding with Christopher Nkunku during pre-season, only for Nkunku to pick up a serious knee injury before playing a competitive minute for his new club. Chelsea, with their history of chewing up forwards and spitting them out, knew the youngster was under undue pressure.

But Jackson has embraced the challenge, defying expectations. He is fast, strong, unselfish and awkward, and his hold-up play is underrated. Some of the flicks and lay-offs are positively Giroud-esque and Jackson’s understanding with Cole Palmer is a source of encouragement. There is, of course, room for improvement.

Jackson scored 14 times in the league and registered five assists last season, although three of those goals came against a nine-man Tottenham. There were, it must be said, some baffling misses. There was more than one long spell without a goal.

But Chelsea were a lesser team when Jackson was missing. He makes space for teammates and causes havoc. There cannot be a defender who enjoys playing against him and the argument that Jackson would have benefited from being the understudy to a more expensive striker ignores the damage that might have done to his confidence and development.

This is a player who is becoming more assured because of a clear pathway. Only Palmer, Erling Haaland, Mohamed Salah and Bukayo Saka have more goal contributions in the Premier League than Jackson’s eight this season. The statistics favour him and he is starting to pass the eye test. Whereas quite a few of his goals last season were scrappy or opportunistic, his strike against Liverpool was proper forward’s play. Jackson bent his run to stay onside and escape his markers, then equalised with a ruthless finish.

There was similar when Chelsea destroyed West Ham last month, Jackson nutmegging Alphonse Areola at his near post to make it 1-0 and adding a second with a nerveless finish after being released by Moisés Caicedo. There was also a close-range header against Wolves, a tap-in against Crystal Palace and a selfless, destructive performance when Palmer’s four-goal haul stole the show against Brighton.

Now the challenge is to push on. Chelsea’s top-four hopes could depend on Jackson maintaining his goalscoring rate. They still feel reliant on him. They fretted about not having an alternative striker when they drew with Nottingham Forest this month. Marc Guiu, at 18, is raw. Nkunku can finish but seems better playing off a focal point. João Félix, Mykhailo Mudryk and Pedro Neto are creative talents who need to produce more.

But none of that is on Jackson. He is outperforming Isak at the moment and is doing all he can to make Chelsea forget about missing out on Osimhen.