Summary
Earlier this past season, Nader was getting more minutes than I expected he would, but after Phoenix traded for Torrey Craig his minutes started to decline, and he also missed some games due to injury. Nader can get to the rim decently, but has never been a great finisher. He's a career 36% three point shooter, which is slightly-above average for a wing, but those mostly come on open spot-up attempts.

Nader isn't a stopper defensively but he's big enough and athletic enough to compete on that end. Nader will be 28 next season, so there's not a ton of upside, but I think he'll still get interest in free agency considering how important it is to have playable wings in today's NBA.
 
Cap Considerations
Nader will be an unrestricted free agent with a $1.7 million cap hold and full Bird Rights, meaning the Suns will have no restrictions on re-signing him.

Other teams will have multiple ways to sign Nader as even teams without cap space could possibly use any of the Non-Taxpayer MLE, Taxpayer MLE, or possibly even the Room MLE or Bi-Annual Exception to sign him. There's also a chance that Nader ends up settling for the minimum.