Luis Enrique: 'Barcelona always open to strengthening' amid Darijo Srna link

Luis Enrique says Barcelona are always looking to improve their squad amid continued reports they're hopeful of signing Shakhtar Donetsk's Darijo Srna in January.

Mundo Deportivo claimed on Wednesday that Barca have stepped up their bid to convince the Croatian full-back to join them.

And asked if the Catalan club would look to do business this month, Luis Enrique said he was open to the possibility of adding to his squad.

"January is a difficult window, but we are always open to any opportunity that would strengthen and improve the team," he said in his prematch news conference for Thursday's Copa del Rey game against Athletic Bilbao.

"I am really happy with my squad, but every team always has to think about ways to improve, that's always true."

Shakhtar coach Paulo Fonseca has previously confirmed he's aware of Barca's interest in Srna, while the Ukrainian club's owner Rinat Akhmetov said the 34-year-old, who's in the final year of his contract, would be allowed to leave for free.

Barcelona's desire to sign the experienced full-back comes after Aleix Vidal fell out of favour.

The former Sevilla player began the season as one of two right-backs at the club, along with Sergi Roberto, but has featured only fleetingly since the shock 2-1 loss to Alaves in September.

Despite leaving him out of the squad for Thursday's game at San Mames, though, Luis Enrique had words of praise for Vidal.

"Vidal, as well as Arda [Turan], has been a positive since his debut one year ago," he said. "They're both important players for the team.

"They arrived in difficult situation and had to wait months to compete, which isn't normal, but both adapted quickly. Arda has had more minutes, Aleix not so many, but both look good, like the rest of their teammates."

Lionel Messi, Luis Suarez and Neymar, who returned to training earlier this week, have all been included in the squad for the Copa del Rey game against Athletic.

With a place in the quarterfinal at stake -- with the second leg to come at Camp Nou next Wednesday -- Luis Enrique anticipates two hard-fought games against the Basque side.

"We know Athletic well, we have played them many times," he said. "It's a difficult tie and we know both legs will be tough.

"[Thursday] in Bilbao -- knowing how good they are [at home] and their dangers in pressing -- should be an attractive game.

"I don't think they will change the way they play. They're a brave team. They essentially try to strangle you and not give you time to breathe on the ball.

"I expect them to be really up for it, especially as it's the Copa del Rey, one of competitions they've excelled in through the years."