By Sedara Oluwadara   Chelsea have signed Marc Cucurella from Brighton and Hove Albion, it was announced on Friday.   Cucurella joins Chelsea in a deal worth an initial £56m with a possible £7m in add-ons.       Cucurella, 24, was wanted by Manchester City and Cucurella handed in a transfer request but the two clubs couldn't strike a deal, with Brighton standing firm on a £50m valuation for the left-back. The deal stalled, as sources told ESPN that City weren't willing to pay the asking price for the transfer, allowing Chelsea to battle for his signature.   CHELSEA'S FIRST GAMES   Aug. 6Everton (A)Aug. 13Tottenham