In eFootball PES, if you don't want to be matched up against a specific player again, you can block them with the ‘Match Block List’ option from inside the game. You can find this option after an online match.
Alternatively, you can go to the ‘Statistics’ section in the Main Menu of eFootball PES and head to ‘Results from last 20 Online Matches’.
From here, select the appropriate match, select the player and add them to your Block List.
Have fun online in eFootball PES!