I didn't have hard players (to this extent, anyhow), but my last two (mother/son "unique blends") had paws as soft as a baby's bottom. Extremes of temperature and anything scratchy to walk on (gravel, mulch) really bothered them.
I used a product called Tuf-foot that you can get on Amazon. It hardens the paw pads without making them dry out. If I recall correctly, you apply it twice a day for...one week?...and eventually three times a week for maintenance. My two had no issues with paws after that. It's designed for hunting dogs walking through brush, thorns, etc. Here's a link:
Tuf-Foot - made to toughen sore and tender foot, paw and hoof conditions (tuffoot.com)
I'd bought it from Amazon and Gun Dog Supply and Jeffers Pet...whoever had it cheapest at the time. Hmmmm.....Canada. Hope that doesn't complicate things for you...the stuff is really good.
If you get it, I'd highly suggest putting a plain cap on the bottle instead of the sprayer (really messy to use spray on a paw without getting it all over and it's yellow) and shaking it with a cotton ball over the opening, not the cap (the cap it used to come with leaked). And dab it on with the cotton ball and let Sully stay on his side till his paws dry (practically instantaneously).