The Catalan press were left to reflect on a bittersweet evening for Barcelona after they conceded late and lost Lionel Messi and Javier Mascherano to injury in a 2-2 draw with Paris Saint-Germain in Tuesday's Champions League quarter-final first leg.

After weathering an early storm, Messi had appeared to put Barca in control of the tie with a fine finish seven minutes before half-time, but he pulled up with a hamstring injury soon after and is now doubtful for the return leg at the Camp Nou next Wednesday.

Mascherano meanwhile is definitely out after suffering a lateral knee ligament injury that will keep him out for six weeks.

"A good but very expensive draw," reflected Barcelona sports daily Sport on its front page.

El Mundo Deportivo struck a similar tone as under the headline "very expensive," they expanded: "Barca achieved a good result in Paris, but lost two key men, conceded an offside goal and another, deflected one, in the last breath."

Indeed other than the understandable frustration at the injuries suffered by Messi and Mascherano, there was much bemoaning the performance of German referee Wolfgang Stark.

PSG's first equaliser arrived 10 minutes from time when ex-Barca striker Zlatan Ibrahimovic prodded home despite appearing to be clearly in an offside position.

Stark was the referee when Barcelona beat Real Madrid in the semi-final first-leg in 2011 that precipitated Jose Mourinho's "why, why, why?" complaint over what he saw as the Catalans always getting favourable decisions in European competition.

"Why, Stark?" sarcastically asked Mundo Deportivo, whilst Sport claimed that only the "injuries and Stark prevented a Barca victory."

However, there was some genuine concern at how the La Liga leaders will cope without Mascherano.

Injuries to Carles Puyol and Adriano have left Barca already extremely stretched at the back meaning either Alex Song will have to play out of position at centre-back or the inexperienced Marc Bartra will start the return-leg.

Moreover, two of the first-choice defenders who are fit, Gerard Pique and Jordi Alba, are just one yellow card away from a suspension should Barca make it to the semi-finals.

"Mascherano breaks down and obliges Barca to improvise," said Gabriel Sans in Mundo Deportivo, whilst in the same paper Fernando Polo argued that in the presumed absence of Messi and Mascherano, it was time for singings in recent seasons such as Song, Cesc Fabregas and Alexis Sanchez to step up.