Santiago was 1-0 in three starts and worked 14 2/3 scoreless innings for Triple-A Charlotte after being optioned on July 30.
"He can do a lot of different things," Ventura said. "He's stretched out and can go multiple innings. You can pretty much put him in anywhere."
Santiago's highest pitch count was 95 during his Triple-A stint and he said his control steadily improved.
"I got a lot better as I went on," Santiago said. "In the beginning, I was trying to throw a lot more offspeed. But the last outing, I was starting guys off with the fastball and then working offspeed to get them out."