No, things really don't look open on clay!
If Goffin had shown some signs of life I'd have loved to see him take on Nadal. But I'll settle for this embarrassment of riches:
1. Pouille in strong form and:
40/2017 R32 Beijing Hard Rafael Nadal Lucas Pouille 4-6 7-6(6) 7-5 1.14 - 5.50
35/2016 R16 US Open Hard Lucas Pouille Rafael Nadal 6-1 2-6 6-4 3-6 7-6(6) 7.00 - 1.08
Pouille loves high balls and will also trouble Thiem.
2. Thiem obviously, but may take a tournament to start finding form after fractured ankle
3. Coric may explode on clay this year and
:
32/2016 R16 Cincinnati Masters Hard Borna Coric Rafael Nadal 6-1 6-3 4.50 - 1.18
43/2014 QF Basel Hard Borna Coric Rafael Nadal 6-2 7-6(4) 7.60 - 1.13
(also great against Thiem)
4. Goffin - probably will find form by RG
5. Zedzilla - he's on the opposite side of the draw from Nadal in Monte Carlo and will guarantee that the rest of clay season if he outperforms Cilic at MC. Zedzilla won't beat Nadal, but still a contender for the prize and matches up well against the rest (never played Pouille).
Looks interesting to me and we have a trial run at Monte Carlo in store with Coric or Thiem likely to hit Nadal in QF.