FOXBOROUGH, Mass. -- During parts of Wednesday's steamy, sizzling practice, and certainly at the end, several New England Patriots looked gassed. They were nicked up, too, with receivers Matthew Slater, Chris Hogan and Julian Edelman all coming up limping at different times.

This is commonplace for this part of training camp, as Wednesday marked the team's sixth practice and fourth straight in full pads.

"Today was a grind," tight end Rob Gronkowski said. "Super humid out. It's getting through the dog days because we just have to keep on pushing through camp."

"Just trying to grind it out," coach Bill Belichick had said before the practice.

This is part of the balance that can be challenging for coaches to strike. Staying on top of conditioning and creating physical and mental stress is a necessary part of training camp -- and fundamentals of football are often best practiced in full pads -- but knowing when to pull back can be equally as important.

It will be interesting to see if Belichick lightens the load on players by taking them out of full pads over the next day or so.

In addition to Slater, Hogan and Edelman getting nicked up in practice, the Patriots' list of players who weren't fully cleared to participate grew on Wednesday and included running back Mike Gillislee, tight end James O'Shaughnessy, receivers Cody Hollister and Malcolm Mitchell, safeties Duron Harmon and David Jones, linebacker Dont'a Hightower, defensive tackle Alan Branch, offensive tackle Andrew Jelks and defensive tackle Josh Augusta.

"This is a big week for us here," Belichick had said on Tuesday to kick off the week. "We've got five practices before Jacksonville [joint practice on Monday] and we've got a lot work to do with third down, down-and-distance, moving the field, situations, kicking game and so forth. So, we need to have a real productive week. I think we got some fundamentals started last week and feel like we're ready to dig into this week here and get after it; that's what we need to do."