The two-time NASCAR Sprint Cup champion is currently in his second season as a team owner in the series. Last year both Stewart and his team-mate Ryan Newman made it into the Chase in the team's debut campaign.
Following this week's announcement of Kahne's multi-year deal with Hendrick Motorsports from the 2012 season, Stewart's team has been tipped as the leading option for Kahne in 2011, as he is set to leave Richard Petty Motorsports at the end of this year.
SHR currently runs chassis and engines provided by Hendrick Motorsports, while it assembles its cars independently at its own shop.
Stewart said on Friday at Texas Motor Speedway that he only learned about the news of Kahne's Hendrick deal this week and that there has not been any talk about him driving for SHR next year.
But Stewart said he would feel comfortable about adding a third car to his line-up, if the right opportunity came along.
"We would definitely with the right opportunity," he said. "Our focus obviously is to keep Ryan's car and our car going well right now. But if the right opportunity and the right driver and the right sponsor came along, we would be definitely interested in a third team as we've said that all along."
Stewart added that Kahne faces the chance of a lifetime by joining the Hendrick roster of drivers, and was full of praise for the 30-year-old, and noting that he had assisted Kahne's passage into the Sprint Cup by suggesting his name to Ray Evernham, Kahne's first boss at NASCAR's top level.
"I think it's a great opportunity for him," said Stewart. "Only Kasey knows what he wants... I know what I've learned in the short amount of time being in the Hendrick system and getting to work with Hendrick Motorsports.
"I've always liked him. I was the one who sat with Ray Evernham and talked to him in the infield at Bristol years ago. So I think it's a great opportunity for him."
Last week at Phoenix Newman scored SHR's first victory of the season, and his first since joining the team last year.
Ronaldo calm ahead of ClasicoJohnson: Keselowski has upset rivals