Xabi Alonso and Bayer Leverkusen could provide financial help to Barcelona this summer

Due to their ongoing financial problems, which do not seem to dissipate soon, Barcelona will be forced to make several significant sales during the summer, as they aim to balance their books before the start of next season. However, another revenue stream for the Catalan giants could also be the activation of the sell-on clause for players who have sold in the past.

Francisco Trincao could be one to fall into this category, with Bild (via MD) who reports that Xabi Alonso's Bayer Leverkusen are interested in signing the 24-year-old, who was officially sold to Sporting CP by Barcelona last summer. Trincao has had a promising season in Portugal, with six goals and four assists in just 12 starts.

As part of that agreement, Barcelona it retained a buy-back clause, as well as a 50% sale. It means they will receive half of any transfer fee Leverkusen will pay Sporting for Trincao, provided they make a move for the Portuguese winger during the summer transfer window.