Right back Cummings spent the first month of the season on loan at West Brom, and has promised to give manager Brendan Rodgers the low down the Baggies ahead of Saturdays meeting between the sides.
Cummings told the Reading post, 'I was at West Brom for about a month so I know how they play and some of the players and how Roberto Di Matteo works. It will be interesting going back, but I`ll be up there to do a job for Reading.'
West Brom have started the season really well and currently sit in 2nd place behind leaders Newcastle but haven't won in their last 3 games and Di Matteo will be feeling the pressure for the first time in his managerial reign at the Hawthorns.
Cummings will be keen to impress after a slow start to his Royals career and will want to prove the West Brom fans that he was right to snub a permanent move there in favour of moving to the Madejski Stadium.