The 29-year-old, who has started up a business venture - a paintball and leisure company called Acton Adventures (www.actonadventures.com) - on his family's farm, is well used to the captaincy role as Ulster's leader for the past two seasons.
The holder of an Agriculture degree from Newcastle University, Best also captained Ireland 'A' against Australia last November.
On the subject of Ireland's touring squad, which is without any of the first choice Six Nations players, and his captaincy, Best said: "There is certainly a lot of motivation within the ranks with big opportunities for the players, with the World Cup in mind.
"I will be looking to guys to step up and take responsibility themselves. Obviously there is a bit of direction needed with the front five, which is my responsibility. But my primary role is to get my own game right and play well."
Best had no qualms about stepping in for O'Driscoll and leading his country.
"Being captain is a role that I enjoy immensely and have been doing so with Ulster for the last few years," he told IrishRugby.ie.
"It is an exciting challenge. Argentina will be well up for the two Tests and it's very important that we focus on getting our own game right.
"We're all looking forward to being part of a winning squad in Argentina."