The Bluebirds have struggled for goals since stepping up into the Premier League, with just 11 recorded in 15 fixtures.
Only Crystal Palace have found the target on fewer occasions, and they continue to occupy a standing inside the relegation zone.
Mackay is aware of the need to address the lack of cutting edge in the final third, but concedes that finding a proven marksman in the New Year will be difficult and costly.
He told WalesOnline: "We are constantly looking at our striking area.
"But at this level, clinical centre-forwards who are proven cost £20m to £25m, and even at that level people still query them.
"At this level, that is not an easy position to fill.
"Stepping into the Premier League is not easy. To put in a player who is going to get you 20 goals in the Premier League, teams are looking all over the world for that.
"The search is always on to find players who can score goals."
Mackay parted with £7.5million over the summer to acquire highly-rated Danish frontman Andreas Cornelius, but is wary of placing too much expectation on a 20-year-old who has struggled with niggling knocks.
He added: "It's helping to have Andreas back now, but he is a long-term option.
"He's someone we have on a long contract and he's young.
"We've got potential there, we've not got a proven, hit-the-ground-running striker. That's not what £7m gets you, that's what £25m gets you in the Premier League. We have young potential here to add to the squad."