NBA.com has a "NBA Playoff Seeding Scenarios" posted.
http://www.nba.com/news/playoff_scenarios_080416.html

3 of the Scenarios have Phoenix playing the Spurs, 2 playing Utah, and 1 playing Houston.

The only thing that confuses me is how does Houston have homecourt in the series against us if we are the 4th Seed and they're the 5th?

.

(Higher Seeded team has homecourt in first round unless otherwise indicated)
1. If Houston and San Antonio win:
3-San Antonio
4-Utah
5-Houston (homecourt)
6-Phoenix

2. If Houston, Utah and Phoenix win:
3-Utah
4-Phoenix
5-Houston (homecourt)
6-San Antonio

3. If Utah wins and Phoenix loses:
3-Utah
4-San Antonio
5-Houston
6-Phoenix

4. If San Antonio and Phoenix wins and Houston loses:
3-San Antonio
4-Utah
5-Phoenix (homecourt)
6-Houston

5. If San Antonio wins and Houston and Phoenix lose:
3-San Antonio
4-Utah
5-Houston
6-Phoenix

6. If Utah and Phoenix wins and Houston loses:
3-Utah
4-Phoenix
5-San Antonio
6-Houston