Pemberton started his career at
Alajuelense but made his league debut for
Carmelita on 11 September 2004 against
Pérez Zeledón when on loan from
Liga. On 15 June 2012 he was awarded the prize for the best goalkeeper of the tournament delivered by Summer 2012 UNAFUT. In December 2013, he extended his contract with Alajuelense four more years. Patrick is currently the goalkeeper with most appearances with the club. Pemberton started on his 300th match on 12 April 2017 against San Carlos for the Verano 2017 tournament, matched previous record holder
Alejandro González Rojas (whose record stood since 23 September 1990 for a total 27 years, one month and nine days) on 29 October 2017 against Saprissa, and obtained his 316th cap three days later against Pérez Zeledón, both matches corresponding to the Apertura 2017 tournament. Previously, in August 2015 Pemberton surpassed José Alexis Rojas, who at the time was the second most-capped Alajuelense goalkeeper with 218 matches. ==International career==