Arsenal’s UEFA Champions League rivals FC Porto are reportedly set to submit an opening offer to sign an FC Barcelona wonderkid linked with the Gunners. The Portuguese giants caused the north London side all kinds of problem this season in their Round of 16 encounter, with Arsenal eventually coming out on top thanks to heroics from David Raya between the sticks in a penalty shootout. Now, the two sides are set to go head-to-head again in the transfer market, with Arsenal and Porto both eyeing up one of Barcelona’s most exciting prospects, who after the appointment of Hansi Flick could now leav…