Barcelona, Oct 14 (IANS): Striker Luis Suarez admits it has been a difficult start to the season for Spanish champions FC Barcelona as last season's treble winners have struggled for form.

Proof of that comes in their two league defeats in just seven matches and the 1-5 aggregate loss to Athletic Club Bilbao in the Spanish Supercup, reports Xinhua.

With star man Lionel Mess out injured for at least another month, the club's relative lack of goals has to be a worry for coach, Luis Enrique, who has seen his side score 12 times in their seven league outings.

Although that may be a decent total for most sides, it is not good for Barcelona and reflects the problems they have had this campaign to break down rival defences.

"We are not packing the same punch in attack as we did last season," confirmed Suarez on Wednesday.

However, the striker drew confidence from the fact that Barcelona had struggled for the first months of last season's ultimately successful campaign.

"Something similar happened then. We won our opening games, but the feeling was that we were not at our best and that something was missing. In the second half of the season everything changed and we played really well."

Suarez expressed surprise at the reaction of some fans at the club's start to the season, which saw some fans actually criticise the side as they struggled to beat German side Bayer Leverkusen in their last Champions League match.

"Last season was incredible with the treble and now after losing a game, people start to judge us already. I don't think there is any sense to the whistling," he said, before referring to the loss of Messi with a knee injury.

"Everything is easier when he is on the pitch, but we have to try and make it easy without him as well. It is not a question of trying to replace him, but we al have to work hard," insisted the striker.

Barcelona's next game sees them entertain Rayo Vallecano on Saturday evening.