Stoke City goalkeeper Jack Butland apparently had a small object thrown at him during the home victory over Aston Villa on Saturday, while Queens Park Rangers said a coin was thrown from among visiting Birmingham City supporters towards home players celebrating their second goal in a 2-0 victory.
"The club will continue to review video footage and liaise with the Metropolitan and West Midlands police," a QPR statement said.
The FA is already investigating an incident the previous Saturday in which West Bromwich Albion's Chris Brunt said he had been struck by a coin thrown by one of the team's own fans after an FA Cup defeat away to Reading.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
"We are aware of the incidents at Stoke and Queens Park Rangers and looking into them," an FA spokesman said.
(Reporting by Steve Tongue; editing by Clare Fallon)
