Fabio Vieira with FC Porto (Photo via Forca.Dragoes on Instagram) For the third game in a row, Fabio Vieira came off the bench for Porto on Sunday.

The Arsenal loanee returned from injury the previous week, coming on as a substitute for 21 minutes against Arouca. He then played 12 minutes against Manchester United in midweek, before his latest 21-minute showing against SC Braga.

In many ways, the appearances are nothing too unusual. Vieira is adapting to a new team after an injury, so it makes sense he'd play a limited role from the bench at first.

Yet it could also be a sign of Porto's unwillingness to pay the penalty clauses in the player's deal.

That obviously incentivises Porto to throw him on even if they don't specifically need him, such as in the Braga game.

Porto were already winning 2-1 against Braga, who have scored the fourth-most goals in the division so far this campaign.

A logical move might have been to try and shore up the defence, something Vieira's introduction was unlikely to achieve. His substitution was more of a like-for-like swap, arguably even an attacking change.

It was the same story against Manchester United, with Porto winning 3-2 when Vieira came on.

But it's one to keep an eye on after the international break. If Vieira continues to make substitute appearances with 20 minutes to go regardless of the sporting circumstances, those cameos start to seem financially motivated.