Arsenal: Čech; Bellerín, Mertesacker, Koscielny, Monreal; Ramsey, Coquelin; Walcott, Özil, Sánchez; Giroud.
Out: Arteta (unspecified), Cazorla (knee), Gabriel (hamstring), Wilshere (calf/shin), Rosický (thigh)
Misses next match if booked: Özil, Giroud, Campbell
Barcelona: Ter Stegen; Dani Alves, Piqué, Mascherano, Alba; Rakitić, Busquets, Iniesta; Messi, Suárez, Neymar.
Out: Rafinha (knee), Arda Turan (suspended)
Misses next match if booked: Piqué
Arsenal 0-0 Hull City
The holders will travel to Humberside for a replay of their FA Cup fifth-round tie after neither side could find the winner in north London. A Joel Campbell free-kick turned onto the post by goalkeeper Eldin Jakupović was the closest either team came.
Las Palmas 1-2 Barcelona (Willian José 10; Suárez 6, Neymar 39)
It is eight Liga wins on the bounce for the Blaugrana, Luis Suárez opening the scoring with his 25th goal in 24 league games this season. The Azulgrana, eight points clear after their Madrid rivals both dropped points, are 32 matches without defeat in all competitions.
Form guide (all competitions, most recent first)
Barcelona have won their two previous two-legged knockout ties against Arsenal, in 2009/10 (6-3 aggregate) and 2010/11 (4-3), and also beat the Gunners 2-1 in the 2006 final at the Stade de France. Current coach Luis Enrique scored in both encounters in the 1999/2000 first group stage, finding the net in the 1-1 Camp Nou draw and again in a 4-2 win at Wembley.