Barcelona manager Ernesto Valverde makes Lionel Messi injury confession

Ernesto Valverde has revealed Lionel Messi has been in pain with injuries since Christmas.

Forward Messi has played 17 times for Barca since returning from the La Liga winter break and also made his return for Argentine for the first time since last summer's World Cup last week.

In that time he has managed an incredible 18 goals to help the Catalan giants extend their lead at the top of the table to 10 points, and qualify for the Copa del Rey final and Champions League quarter-final - where they will face Manchester United .

But while he was on international duty in South America, Messi suffered a groin injury against Venezuela - which forced him back to Spain to get treatment.

The 31-year-old is expected to be fit to play for Barca in their La Liga clash with city rivals Espanyol on Saturday.

Ernesto Valverde has admitted Lionel Messi hasn't been at full fitness (ALEJANDRO GARCIA/EPA-EFE/REX)

Philippe Coutinho tells teammates he wants to leave Barcelona this summer

But manager Valverde has admitted that his superstar has been struggling for at least half the season and that the club has placed the five time Ballon d'Or winner on a specialised training plan.

"We think it's OK but he has been coping with these issues for a long time," Valverde said.

"We were taking care of it before Christmas. We have tried to make the pain subside and we will continue doing it. Now he has had a few days of rest.

Messi suffered a groin injury on international duty (Rodrigo Jimenez/EPA-EFE/REX)

Despite his pain, Messi has been in good form (AFP/Getty Images)

Gerard Pique reveals what Lionel Messi is really like away from the limelight

"We do everything naturally, we talk to him after suffering a little problem in training and we do everything together. We make decisions together and talk to him to see how he is like I do with others."

Valverde has also warned his stars and fans that despite their strong position in all three competitions nothing has been won yet.

The Spaniard said: "The environment escapes me, we have not won anything yet.

Messi is likely to be available for Barca's clash with Espanyol (ALEJANDRO GARCIA/EPA-EFE/REX)

"Every time they tell me about the treble and the double. What we're not going to deny is that people get excited about the team.

"We are in three competitions and I imagine that people will celebrate the options we have, but we have not won anything."