Britain are bidding to defend the title, which they won in Belgium last year, for the first time since 1936 and will be the favourites ahead of this weekend’s tie in Glasgow.
Murray, the world number two, will take on the towering Del Potro at 1:00pm local time on Friday before Kyle Edmund takes Guido Pella in the reverse singles.
Britain captain Leon Smith has decided to drop doubles specialist Dom Inglot from the four-man squad, with Jamie Murray set to play alongside brother Andy in Saturday’s doubles rubber.
Dan Evans, who has recently reached a career high of world number 53, will take the final spot in the team and could play a part in Sunday’s reverse singles.
Del Potro and Murray set for Olympic final repeat
Del Potro, the US Open Champion in 2009, is the star name for the Argentines but will play as his country’s number two because his ranking of 64 in the world- that is lower than Pella at 49.
That is a result of Del Potro’s lengthy wrist injury, however the Argentine appears to be back to his best after reaching the quarter-final of the US Open last week- losing to eventual champion Stan Wawrinka.
Federico Delbonis and Leonardo Mayer have been named to play the doubles for Argentina, though captains are allowed change their line-ups up to an hour before the match.
Tough decision for Smith
Smith admitted that the decision to select Edmund over Evans for second singles spot was a difficult one, after both reached their career high rankings last week.
"It's a difficult choice because both Dan and Kyle are playing great tennis," said Britain’s captain. "They're pretty much neck and neck in the rankings, they both have really good Davis Cup experience now.”
Edmund and Pella have met just once before. It came at Indian Wells earlier this year when the Argentine won in three sets.
The other semi-final sees Croatia host France in Zadar.