The Croatian, 35, has returned to form with a deep run at the Hall of Fame Championships in Newport after just one win in his previous five tour-level matches.
However, the big-serving veteran will have to transfer his grass-court form to the hard courts of Colombia, where he returns to defend an ATP Tour title for the fifth time.
Karlovic has successfully defended a title once before, going back-to-back in Nottingham in 2007-08.
The top seed for the ATP 250 event will be 14th-ranked Frenchman Richard Gasquet, who made the Eastbourne final in June before a second-round loss at Wimbledon to Nick Kyrgios.
Gasquet's loss to Kyrgios was overshadowed by the teenager's victory over Rafael Nadal later in the tournament, however Gasquet did also struggle to beat another lowly ranked Australian James Duckworth in the first round, a match which went to five sets.
Other top-50 players confirmed to appear in Bogota include Canada's Vasek Pospisil and Czech Radek Stepanek.
Australia have a strong contingent at the event, with Matthew Ebden, Samuel Groth and Bernard Tomic all appearing, with Groth - like Karlovic - playing himself into form at Newport.
Alejandro Falla, who lost in the final to Karlovic in 2013, is the leading local hope, alongside Alejandro Gonzalez.
Falla, 30, was in his first career tour final 12 months ago, and doubled his tally of finals when he reached the decider in Halle in June - when he lost to Roger Federer.
Gonzalez is ranked 72nd, and will be keen to break his duck at the tournament after a first-round exit to Adrian Mannarino last year.