Barcelona and Manchester City’s pairing in the Champions League group stage is one of the more intriguing stories in the world of football this season, with Barca legend Pep Guardiola returning to his old home as City boss.

And while the Catalan side are arguably the greatest side in world football at present, City have their own stellar cast: Kevin De Bruyne, Raheem Sterling and Sergio Aguero are a frightening proposition for any side.

And so to the line-ups. De Bruyne – check. Sterling – check. Aguero… Sergio? Oh.

TEAM NEWS | Here’s how City line-up at the Camp Nou tonight! #FCBCity #mcfc

— Manchester City (@ManCity) October 19, 2016

No Aguero in City's starting XI tonight:

— Coral (@Coral) October 19, 2016

The man who’s scored six Champions League goals already this season was left on the bench.

Kun Aguero on the bench!

— Guillem Balague (@GuillemBalague) October 19, 2016

Furthermore, he couldn’t be seen emerging with his fellow substitutes either. Very strange…

Aguero is the only one of the seven subs not out warming up. #MCFC

— Stuart Brennan (@StuBrennanMEN) October 19, 2016

Aguero has not even emerged to warm up with City's other subs. Something amiss there #MCFC @mirrorfootball

— David McDonnell (@DiscoMirror) October 19, 2016

Pep’s certainly a brave man. We’re not sure City fans will have enjoyed this particular surprise, however.

Leaving Aguero on the bench is a bit reminiscent of Guardiola defending 3 v 3 at Bayern against Messi, Neymar, Suarez. He likes a surprise.

— Paul Hayward (@_PaulHayward) October 19, 2016

What exactly is going on?

Is it too easy to suggest Pep's not entirely happy with Aguero? Gabriel Jesus brought in to put pressure on him, Aubameyang chased in summer

— Sam Lee (@Sammy_Goal) October 19, 2016

Guardiola's demands for more from Aguero feel like more than just motivational tactics

— James Robson (@JamesRobsonMEN) October 19, 2016

After much speculation, Pep confirmed that it was purely tactics, which leaves more questions than answers…

Pep Guardiola has confirmed that Sergio Aguero's place on the bench is based on a tactical decision.

— Squawka News (@SquawkaNews) October 19, 2016

Although maybe he’s onto something…

Sergio Aguero is on the bench. But it's not all bad news.
Champions League win rate
With Aguero – 34%
Without Aguero – 71%

— BBC 5 live Sport (@5liveSport) October 19, 2016

Let’s see how this one pans out.