Littler returns to action on Thursday as he makes his Premier League Darts debut in Cardiff, with live text commentary on the BBC Sport website and app from 19:00 GMT.
He will again face Humphries in the quarter-finals, with Cardiff the first of 16 events in the tournament.
Ranking points are awarded on each night, with the top four players overall heading into the play-offs at London’s O2 on Thursday, 23 May.
Premier League, Cardiff – quarter-finals
Order of fixtures to be confirmed
Peter Wright v Rob Cross
Gerwyn Price v Nathan Aspinall
Michael van Gerwen v Michael Smith
Luke Littler v Luke Humphries
