Gatland has still not ruled out the prospect of O'Driscoll assuming the Lions captaincy for a second time, despite Declan Kidney's decision to replace the Leinster centre as Irish skipper.
However, Gatland has warned that fitness concerns will play a significant part in his decision and he has also been impressed with Heaslip's impact since he assumed the role of Ireland captain last November.
Heaslip, who once again reiterated his delight at being named the Irish captain at the Six Nations launch in London, will also face stiff competition from the long-term favourite to captain the Lions, Welsh openside Sam Warburton.
However, Warburton has struggled to maintain the form that brought his side to a World Cup semi-final and a Grand Slam, and Gatland is eager to ensure that his captaincy selection is a first-choice player.
But Warburton, who led Wales to the Grand Slam last season after following up their 2011 World Cup quarter-final win over Ireland with victory in the opening game of the championship last season, has roared out a warning ahead of the sides' meeting in Cardiff.
"People are talking about Welsh rugby as if it has completely gone down to the pan, (but) it is easily recoverable,'' blasted Warburton.
"You don't become a bad side overnight, just like you don't become a good one. It is a really nice feeling going into the tournament as reigning champions. We can take great confidence from that."
Wales, who will be led by assistant coach Rob Howley while Gatland attends to his Lions commitments full-time, are hopeful that their injury crisis may ease somewhat with both Ryan Jones and Ian Evans expected to be fit for their crucial February 2 championship opener.
"Ian and Ryan are being assessed on a daily basis and it is still very much positive at this moment in time," revealed Howley at yesterday's launch.
"That will continue and we will know more on Monday. It is just the healing process for Ryan, thankfully there is no fracture of his thumb. We are confident he will be available for the Ireland game."
Meanwhile Leinster are still hopeful that Jonathan Sexton will spurn Racing Metro's unconfirmed ¿750,000 deal and sign on with the IRFU for at least another two seasons.
Out-half Sexton is still mulling over an IRFU offer that could make him the highest paid rugby player in the country with a deal expected to be concluded before the Six Nations kicks off against Wales on Saturday.