Riley was given a straight red and two-match ban for violent conduct after tangling with Hearts defender Kevin McHattie in the 1-0 home victory over Hearts on April 27.
However Dark Blues boss John Brown will be able to call upon the services of defender Kyle Benedict after he served his own one-match suspension.
Dundee are unbeaten against Killie this season after drawing their first two meetings 0-0 and then claiming a 2-1 victory at Rugby Park on April 6.
Ninth-placed Kilmarnock have no fresh injury worries ahead of their trip to Dens Park.
Defender Lee Ashcroft is on the comeback trail following injury but the game is likely to come too soon.
Longer-term casualties Manuel Pascali, James Dayton and Rory McKeown remain on the sidelines.
Young Kilmarnock striker Ross Davidson was handed his first start for the Ayrshire club in last week's abandoned game against Hibernian and is hoping for another chance.
He said: "There are a few games to go and I would like to start those games but I just have to do what I can do and hopefully impress the manager.
"Hopefully the manager keeps the same team because I thought the team did well. We will just have to wait and see how things go."