The 24-year-old was sent home from the recent tour of South Africa without playing in the Test or one-day series after developing a shin problem as a complication from an existing ankle injury.
"Gul is fine now and has been bowling in the nets with the team. His availability is a big boost for the team," team coach Bob Woolmer told reporters on Tuesday.
Gul, who has taken 30 wickets in 25 one-day internationals, is considered as key member of the bowling attack with doubts remaining over new-ball pairing Shoaib Akhtar and Mohammad Asif for the March 13-April 28 tournament.
Woolmer said he had no new details of Shoaib and Asif's progress, with the pair receiving treatment in London for their knee and elbow injuries.
"Gul is the most improved bowler over the last year," Woolmer said of the injury-prone player, who also has 61 Test wickets.
Pakistan are in Group D of the World Cup with all their pool matches being played in Kingston, Jamaica. The open their campaign on March 13 against hosts West Indies, with Zimbabwe and Ireland making up the four-team group.
