Furniture Leveler PTFE(Teflon) Bottom(28mm Base),Threaded Shank(1/4-20) Adjust Pads,Table/Chair/Cabinet/Sofa Medium Adjustable Legs Leveling,Nuts Installation and Floor Protection(8 Pack)

You could add some glides (not necessarily these ones but they come in lots of different sizes) or just shim it in place. Overall, unless it rocks noticeably when you sit in it I would accept it as is.