The Reading striker had led calls to not support the T-shirt campaign ahead of this weekend's fixtures after voicing his opinions that the organisation is not doing enough to stamp racism out of the game.
|DON'T BOYCOTT CAMPAIGN - WENGER
"The four-match ban was, for me, not a heavy enough sanction for what happened," Roberts said in the week.
"I'm totally committed to kicking racism out of football but when there's a movement I feel represents the issue in the way that speaks for me and my colleagues, then I will happily support it.
"I think people feel let down by what used to be called 'Let's Kick Racism Out of Football.'
"People don't feel like they have been strong enough."
Kenwyne Jones was another player at Old Trafford who chose not to wear the shirt, while Roberts' Reading team-mate Garath McCleary did likewise.
Micah Richards was another to refuse to acknowledge the campaign, although Patrice Evra, who was racially abused by Luis Suarez last season, did wear the shirt, as did the Uruguayan at Anfield.