There were worries that the former Aston Villa man would be set for an extended stay on the sidelines after sustaining a knee injury against Millwall.
But Whittingham, an ever-present before the win at Birmingham, may just miss his side's FA Cup tie at Macclesfield along with left-back Andrew Taylor.
"Peter Whittingham tweaked a knee in our match against Millwall and wasn't quite ready," Mackay told the club's official website.
"Andrew Taylor fell ill and was feeling dreadful, so we sent him back to South Wales by car.
"We're hopeful they will both be ready for our next league match against Ipswich on Saturday week."
The Bluebirds are now seven points clear at the top of the table ahead of their FA Cup third round tie this weekend.