West Brom said on Friday they had contacted the police and would seek the toughest possible punishment after a racist message was sent to the 29-year-old Saint Kitts and Nevis international on social media.
"We've arrested a man on suspicion of racially abusing West Bromwich Albion player Romaine Sawyers online," West Midlands Police said on Twitter late on Friday.
"The 49-year-old man from Kingswinford was this evening taken into police custody for questioning.
"Our dedicated football hate crime officer is also investigating another report of a racist comment towards the same footballer. We will not tolerate racism."
Government ministers met top English players on Monday to discuss online abuse and discrimination as part of a series of "Future of Football" discussions.