Dundee will be without striker Carl Finnigan against visitors Ayr after he picked up a knee injury in the 1-1 draw with Raith Rovers on Saturday.
Winger Nicky Riley is also unavailable due to a back injury and defender Rhys Weston is also struggling to feature due to the knock he picked up against Livingston at the beginning of the month.
The Dark Blues have fallen 17 points behind Ross County, however manager Barry Smith is determined that his men do not switch off.
"Ayr drew here in August and they have improved since then. We need a very decent performance to win this one," he said.
"They are coming here with plenty to play for but I am expecting us to go out and get the three points."
Eighth-placed Ayr will be without two key players as they travel looking to take another step towards First Division survival.
Midfielder Jamie McKernon, who has a hip problem, and broken foot victim Sean Higgins will both miss out.
Manager Brian Reid said: "Some people are saying that we are edging towards safety but all I am focusing on is picking up three points from this game."
Reid looks set to freshen up his side saying for the Tayside clash and added: "We did not play well against Morton at the weekend and we looked short of energy.
"Our substitutes gave us a real lift when they came on and it may that they have played themselves into a starting role in this game."