Steve McClaren’s men are odds-on to pick up their first win of the season against struggling Rovers.
Using bwin’s free £25 on a Motherwell win over Inverness will see new customers pick up returns of £50.
The Dons are priced by bwin at 19/20 to secure an opening day victory against St Johnstone.
Rangers thrashed Hearts 4-0 last time out and are favourites to win their season opener with bwin offering odds of 7/20 on a home win.
Fulham are priced at 1/100 to win the second leg, leaving punters to look elsewhere to spend their free £35 bet.