Injured Arsenal defender Gabriel Paulista has returned to Brazil to undergo treatment for a hamstring injury that kept him out of the win over Leicester last weekend.
The centre-back is currently sidelined is back at former club Vitoria, who he played for between 2010 and 2013, to receive treatment for the problem.
Gabriel has played 16 times for Arsenal in his first full season with the club after joining the Gunners in January of last year.
Arsenal FC hope it will be a case of third time lucky when they host FC Barcelona in the first leg of their UEFA Champions League round of 16 tie.
The Premier League side have lost their two previous knockout ties against Barcelona, who won in England at this stage of the competition in both 2014 and 2015. Arsenal will be looking to reach the quarter-finals for the first time since 2010.
They reached the knockout stage for the 16th season running thanks to a 3-0 win at Olympiacos FC on 9 December. They had lost three of their first four group games but finished as group runners-up thanks to a superior head-to-head record against Olympiacos.