The Norwich City striker shake-up was set up well to be dramatic this summer.

Every runner and rider had their own storyline after a disconcerting season under David Wagner, with each desperate to further their career and play a key role at Carrow Road or elsewhere.

Adam Idah was already locked into a transfer saga with former loan club Celtic. Josh Sargent was already battling an ankle injury that had caused concern for months among the fan base. Ken Aboh was already subject to contract questions, and Ashley Barnes was battling the 'Wagner's player' tag he'd already been given.

What City did not need was another twist in the tale, with surgery on Barnes' calf injury adding complication to a field already brimming with it. He's set to miss the start of the season and could be absent for weeks after that, a less than ideal development for Norwich.

But that's the card they've been dealt, and suddenly Johannes Hoff Thorup's options have shrunk for a considerable portion at the start of the season. Many will point to the fact that he was likely behind Sargent in the pecking order, but that only remained the case for four games last campaign.

Injuries have been a big part of each of the Canaries' recent seasons, and losing players can be transformative even if they don't make the first starting line-up of the term.

Of course, many of the signs have suggested a different Idah, more confident and ready than the one who produced another false dawn in his American team-mate's absence. But his previous record in the second division is unreliable, even if he has created a series of magical moments.

In 70 Championship appearances he's scored 11 goals, with consistency rare and patchiness plentiful. Even the Irishman's most vehement supporters will admit that he's a long way from reaching his full potential.

But pre-season has been encouraging, of that there's no doubt. Impressive showings in Belgium included a well-weighted assist for Borja Sainz's opener at Standard Liege, while the 23-year-old's hold-up play was a highlight.

Replicate that often in yellow and green and he'll make the attacking picture look much more secure, but much of the debate surrounds whether he'll even be in Norfolk next season.

Celtic's interest in Idah remains a big part of the discussions around Thorup's forwards, and the current financial parameters mean every player has their price. The difference between what that is for sporting director Ben Knapper and the Scottish champions remains the reason why he remains at Norwich, however, and it seems to be a fairly large one.

Perhaps Barnes' absence would mean an improved standing for Idah, and potentially a powerful tool for someone so augmented by confidence. But to start he'll have to get past Sargent, and that's no simple task.

Celtic still hope to sign Adam Idah permanentlyCeltic still hope to sign Adam Idah permanently (Image: PA)

The Norwich number nine has been the missing piece of the pre-season jigsaw so far, delaying his return for international commitments and sitting out of team training until now. With an ankle severely tested in recent months fans were worried about his fitness, too.

The feeling behind the scenes, however, is that he's fully recovered and will be ready for action before long. That should make the picture slightly clearer, but again transfer speculation takes away any certainty.

Sargent is one of few high-value players who could make a significant profit for their club this summer, the like of which is very much needed by City. If he's sold he'll almost certainly need replacing, and any hopes of doing that by promoting from within rest largely on one man's shoulders.

That's a lot of pressure to put on 19-year-old Aboh, in many ways the wildcard of the discussion. His run-out for the under-21s at Wroxham indicates where he's seen in the current pecking order, even if his potential is clear.

There could well be twists and turns to come in a story that might not be finished by the time Thorup and his charges travel to Oxford on the opening day. Barnes' injury setback might feel like a minor one, but the knock-on effects highlight how many elements are at play.