求问以下句型
CaughtOffside understands that the Gunners are closing in on an agreement for the French youngster to move to north London in a £23.5m deal,with the option of a buy-back clause for Real should they look to re-sign him in the future.with the option of a buy-back clause for Real should they look to re-sign him in the future.这里的 should they look to re-sign him in the future是什么用法?