Seppi had to withdraw from the League as he will undergo a surgery due to a hip injury.
Giraldo, world number 70, had last year beaten Lleyton Hewitt, Jo-Wilfred Tsonga and Andy Murray en route to Madrid Masters quarterfinals. He had also reached the final of the Barcelona Open, an ATP 500 event, last year.
"I am very happy to be coming to India this year to play in the Champions Tennis League Season Two. I'm also ready and excited to play for Mumbai Tennis Masters with some amazing players like Krajicek and Pennetta. I hope to have a great time there and here's to Champions Tennis League 2015 - Bigger, Better, Stronger," Girlado said.
The second edition of the CTL will commence from November 23 and will see 13 matches played over a two-week period.
CTL will feature six city based teams across India. The teams will be structured into two zones, each having three teams, where all teams play each other in a home and away format.