According to the club. He's not injured.
There's a good thread where you can check this stuff.
http://www.northstandchat.com/showthread.php?365486-Hughton-and-Injuries-tracker-2018-19/
David Button isn't injured.
"he had a slight knee problem" a month ago
https://www.theargus.co.uk/sport/17210790.albion-winger-alireza-sidelined-for-cardiff-game/
since then he's recovered but Steele has 'edged ahead" in terms of being the #2...