Barcelona reportedly face a challenge from Premier League champions Chelsea in the pursuit of emerging Gremio midfield star Arthur, a player who sparked controversy after being photographed in a Barça shirt last week.

Arthur, a Copa Libertadores winner with Gremio this year, is thought to have been scouted by Barcelona for some time, with technical secretary Robert Fernandez personally heading to South America to watch him in action in the two-legged Libertadores final.

Lanus v Gremio - Copa CONMEBOL Libertadores 2017

But the image of the 21-year-old in Barça colours alongside Camp Nou representative Andre Cury has unsurprisingly angered Gremio.

According to the Daily Mirror, Chelsea are showing interest in Arthur and potentially see the Brazilian as a long-term successor to 30-year-old Cesc Fabregas.

He is thought to have a €50m (£44m) release clause and the Barça shirt incident may even assist Chelsea in their efforts if Gremio are disinclined to now sell to the Catalans - the immediate reaction from the Porto Alegre club when the picture surfaced last week was that they will not be negotiating with Barcelona.

Triggering the €50m clause may be the only way that La Liga's leaders can strike a deal, with the player seemingly very happy to head to Camp Nou.

Were Chelsea willing to make an approach to Gremio there is a chance they could negotiate the price down from €50m more easily.

Gremio v Sao Paulo - Brasileirao Series A 2017

Chelsea have had mixed success signing players directly from Brazil. Oscar arrived from Gremio rivals Internacional in 2012 and enjoyed several good years at Stamford Bridge before having his head turned by a lucrative offer from the Chinese Super League.

Others like Alexandre Pato have proven to be less good, while the jury is still out on Kenedy.