https://www.fcbarcelona.es/futbol/barca-b/noticias/2017-2018/el-fc-barcelona-y-carles-alena-han-llegado-a-un-acuerdo-para-la-renovacion-de-su-contrato?_ga=2.267074572.307908468.1498380867-2029036341.1493131280
3년 + 1군 승격시 2년 연장 가능
https://www.fcbarcelona.es/futbol/barca-b/noticias/2017-2018/el-fc-barcelona-y-carles-alena-han-llegado-a-un-acuerdo-para-la-renovacion-de-su-contrato?_ga=2.267074572.307908468.1498380867-2029036341.1493131280