Barcelona are keeping close tabs on Porto defenders Eliaquim Mangala and Nicolas Otamendi, according to Catalan daily newspaper Sport.
It is no secret the Catalans are hoping to add at least one high-profile centre-back to their ranks, and the Porto duo appears to be high on their hit-list.
The problem is that they could face stiff competition for both players, who are reportedly on the radar of top European clubs.
And while Mangala’s release clause stands at €50 million, Otamendi would be available for €30 million, whereas Porto chiefs are not exactly prepared to negotiate the asking price.
Barcelona have yet to make any concrete moves, but with Carles Puyol nearing the end of his career and Javier Mascherano linked with a summer exit, they may be forced to act in the near future.
Even with the Catalans now tied on points with second-placed Atletico Madrid, they remain 4/6 favourites for the La Liga title.