The 21-year-old arrived for £25million, however, he quickly became a peripheral squad figure and was restricted to late substitute appearances in the Premier League and rare starts in the domestic cups. There was even talk in January that he could be sold at a loss just six months after arriving.
The dynamic has shifted a little recently, though. Iheanacho is starting to make an impression at Leicester, as demonstrated by his performance against 4-1 away victory.
This weekend Leicester face Chelsea for a place in the FA Cup semi final. It's a challenge that might suit Iheanacho.
The Nigerian has four goals in four appearances in the world's oldest club competition this season. While he has struggled in the top flight, the Nigeria international has thrived in the Cup. He and Claude Puel will hope that continues.
Iheanacho is, by trade, a penalty box operator. He will not often sprint behind defences, like Jamie Vardy, or be full of boundless energy, like Shinji Okazaki. And this is perhaps why he has been afforded so few opportunities during his time at Leicester.
He is a man who thrives on service in the 18-yard box, when he doesn't get it his influence wanes. The Nigerian is averaging 0.7 shots on goal per game this term, far below the all-action Vardy (1.8) and tireless Okazaki (1.2).
The Foxes are still using the counter-attacking game plan that took them all the way to the title two years ago, with the 4-4-1-1 and 4-2-3-1 shapes conducive to that approach.
Puel has switched between the two systems since his arrival at the club in October, but the one constant has been his use of a lone frontman – Vardy.
Leicester average 72 long passes per match and that is because their tactical plan is focussed around trying to get the England international running at the opposition goal at pace.
This, of course, puts Iheanacho at a disadvantage. He was signed to broaden Leicester’s attacking horizons but finds himself in something of a catch-22 scenario. He needs game time prove himself, but rarely gets it because he doesn't fit in stylistically.
Puel has, on occasion, taken to using young frontman as a support act behind Vardy and it's a role he has taken to surprisingly well – he's averaged 0.98 open play key passes per 90 in the Premier League.
It's from that position as a second striker that Iheanacho impressed against West Brom, and Puel now has to decide whether to trust the striker against Chelsea.
A strong performance coupled with a win over Antonio Conte's side at Stamford Bridge, would prove Iheanacho is finally comfortable in his new surroundings at Leicester. Yes he's young and there will dips in form, but make an impact when called upon and it won't be long until he's a regular.
“I need to get involved and help the team,” Iheanacho said after the win over West Brom. “We’re looking forward to playing against Chelsea. They’re a good side, a strong side. We’ll just keep working hard in training and we’ll be ready for them.”
Will his hard work pay off? Only Puel knows. But if Iheanacho is given the nod against Chelsea, he’ll have the opportunity he’s waited all season for at Leicester. It will be one he must take.