Gun Runner breezed a half mile at Gulfstream Park on January 22 in his last timed workout ahead of his career finale in the $16 million Pegasus World Cup on Saturday.

Gun Runner, co-owned by Winchell Thoroughbreds and Three Chimneys Farm, will be the morning line favorite for the Pegasus World Cup, the world's richest race.

He is aiming to extend a four-race winning streak in G1 races in the 9 furlong contest.

On Monday with exercise rider Angel Garcia aboard the 5YO son of Candy Ride worked the half mile in 48.96 seconds. He galloped out to five furlongs in 1:02.11. His easy four-furlong breeze ranked ninth-fastest of 15 at the distance.

"I loved how he did it," said Scott Blasi, chief assistant to trainer Steve Asumssen. "Angel was really happy with him.”

Gun Runner won the G1 Breeders' Cup Classic at Del Mar on November 4 and has been training for the Pegasus World Cup at Fair Grounds in New Orleans.

He shipped to Gulfstream on January 18. Blasi said Gun Runner handled the move to South Florida and the new surface without incident.

"He's just been really special to us and he continues to do exactly what you want him to do," Blasi said.

"I'm just really happy with how he got over the ground. He's cooling out great and is ready for Saturday."

Blasi acknowledged that it can be difficult to judge Gun Runner's workouts visually.

"That's just kind of Gun Runner. He just does stuff so effortlessly," Blasi said.

"You think that he's not going anywhere, then you look down at your watch.

“This year he has gotten stronger and faster. There's just a lot more to him."

Gun Runner has won 11 of his 18 career starts and $US8,988,500.

A victory in the Pegasus World Cup, with the winner's share worth $7 million, would move him into second place in career earnings for a North America-based horse behind last year’s winner Arrogate.

Gun Runner is scheduled to retire after the Pegasus tol begin his stud career at Three Chimneys Farm in Kentucky.