Osasuna defender Fernando Macedo da Silva knows there is plenty to fear from Barcelona after they followed up defeat in the Primera Division with a solid victory over Malaga in the Copa del Rey quarter-finals.
Barcelona set up a Copa del Rey El Clasico semi-final against Real Madrid thanks to their 4-2 win on Thursday, but they still have the small matter of a league match against struggling Osasuna on Sunday before their cup showdown.
The first leg of the cup semi-final takes place in Madrid on 30 January, with the return at the Nou Camp four weeks later, and Barca striker Lionel Messi is expected to be fit despite being substituted late in the game against Malaga.
The Argentinian was taken off as the adductor in his right leg was giving him problems, which Barcelona assistant head coach Jordi Roura has since played down as a preventative measure.
Barcelona slipped up in their last Liga clash losing 3-2 to Real Sociedad, while in contrast, Osasuna claimed a much-needed 2-1 win over relegation rivals Deportivo La Coruna after they held Real Madrid to a goalless draw.
"You could see yesterday that is a great Barcelona team," Macedo da Silva told AS.com.
"Playing on a big field, they are difficult to defend against.
"We face a major rival and we have nothing to lose. The win against Deportivo La Coruna finished with all the desire and all the excitement, and was three very important points for us."
And the 30-year-old former Spain Under-21 international does not think Barcelona will be particularly weakened if Messi does not recover from his muscle problem.
He said: "These players want to play every game. Messi plays, otherwise someone else will do so in his place and will do just as well."
Barcelona playmaker Xavi is conscious of the forthcoming media hype surrounding the cup match-up with Real but is first focusing on rebuilding a long winning streak in the league.
Before the defeat by Sociedad, Barca were unbeaten in the league this season, a run of 19 games without defeat.
Xavi said: "El Clasico is built up in the media. In the league we will look to start a new streak.
"(Osasuna coach) Jose Luis Mendilibar will be looking to tighten us up and make things difficult for us."