Alcaraz climbed to the top of the ATP rankings in September after winning his first Grand Slam title at the US Open but a torn abdominal muscle during the Paris Masters in November put the teenager out of action.
After 20 weeks at the top, Alcaraz slipped to number two in January when Djokovic won the Australian Open, an event the Spaniard had to skip due to injury.
"It has been a long time (I spent) at number one," said Alcaraz, who begins his season in Buenos Aires against Serbian Laslo Djere in the second round.
"Now it's a goal for me to recover number one and try to do my best in these tournaments to be back on that number. I'm looking for that."
Alcaraz did not want to put too much expectation on himself in his first tournament since November.
"I'm feeling great. I'm getting used to these conditions, to play with the best players, so at the moment I'm feeling well," he said.
"It's tough to play my first tournament after a long time for me, after four months.
"So it's going to be really, really tough to win the tournament or be close to winning. My hope is to feel that I am okay with the injury, with my body and try to play well."
