Barcelona undecided whether to sign Gremio's Arthur or Schalke star Leon Goretzka

Barcelona are reportedly set to decide on signing Gremio star Arthur Melo or Schalke's contract rebel Leon Goretzka to further strengthen their squad.

According to Spanish publication Mundo Deportivo, the Catalan club will have to make a decision on whether to sign the Brazilian midfielder or Goretzka. Both the players are a transfer target for the Blaugrana.

The La Liga leaders have decided to bring in four new players to give more options to their manager Ernesto Valverde. Liverpool star Philippe Coutinho remains a priority for the former Athletic Bilbao manager.

Atletico Madrid forward Antoine Griezmann has also been identified as a transfer target, along with the Reds' Brazilian star. Barcelona have identified that they need to further strengthen their "core."

Gremio midfielder and Goretzka have been identified as the other two targets, out of which they are planning to sign only one player. The Spanish giants are financially capable of signing both the midfielders, but that would only lead to more number of midfielders in the squad.

Valverde already has the services of Sergio Busquets, Andres Iniesta, Ivan Rakitic, Paulinho, Andre Gomes, Sergio Roberto, Denis Suarez and Rafinha. The arrival of Coutinho will further improve the competition in the squad, but he is capable of playing in the front three as well, while Roberto can be deployed in the defence or wide position.

Arthur has been heavily touted by Barcelona, while their arch-rivals Real Madrid are believed to be in the race for his signature. Gremio president Romildo Bolzan has confirmed his side are yet to receive a formal offer and stressed the Brazilian will be only allowed to leave if the interested clubs can pay his full release clause of €50m (£44.3m, $59.4m).

He is eyed as one of the brightest prospects coming out of Brazil. Arthur has the potential to develop into a top quality midfielder in the coming years. However, any approach in signing him will see them spend big.

With Goretzka, his contract with the Bundesliga outfit will run down after the end of this season. Schalke have already offered a new deal worth €12m-a-year (£10.6m, $14.4m). However, the player has decided against signing a new deal.

He is available for a free transfer in the summer but will have to provide him with a signing on bonus and also a hefty fee for his agent. Signing Goretzka could still be relatively cheaper than Gremio's Arthur.

Barcelona are not the only club interested in signing the midfielder. Premier League clubs Arsenal, Manchester United, Manchester City, Liverpool, along with Bayern Munich and Juventus are also looking at landing him.

It is believed the Merseyside club now are the front runners in landing Goretzka after he emerged as a transfer target for Jurgen Klopp. The former Borussia Dortmund manager has insisted Liverpool to sign Schalke midfielder.

Barcelona officials Pep Segura and Robert Fernandez will have to make a decision whether to sign Arthur and Goretzka after consulting Valverde.