Paul Pogba and Amad Diallo held up a Palestine flag at the end of Manchester United's 1-1 draw with Fulham in the Premier League on Tuesday.
France international Pogba appeared to be given the flag by a United fan at Old Trafford, as the players made their way around the pitch at full-time after the last home match of the season.
On Saturday, Leicester's Hamza Choudhury and Wesley Fofana celebrated their FA Cup final win over Chelsea with the Palestine flag at Wembley.
The displays come amid renewed conflict between Palestine and Israel and have been interpreted in some quarters as a political gesture.
The Leicester pair were not punished for the display, however, as it is understood the Football Association does not investigate the general use of flags on the field of play.