While it's not 100% sure that De Colo will sign with Spurs, this rumor seems to be really strong.
A french journalist (Pascal Giberné) has contacted his agent. A quick translation about what he is saying on his twitter about that:
https://twitter.com/#!/PascalGibBN
- Nando De Colo's agent, Wassim Boutanaos, seems to be confident about his client playing for Spurs next year.
- Boutanos talked ten days ago with Dennis Lindsey Spurs assistant GM. Talks were encouraging.
- According to Boutanos, De Colo's singing will depend on what kind of contract Duncan will get.
- Boutanos quote: "Dennis Lindsey told me that in all their projections for next year roster, Nando was a part of it."
- According to Boutanos, most of the big Spanish teams playing the Euroleague are also interested in De Colo.