The Clarets keeper, who has started all 137 league games for the club since arriving in the summer of 2013, pulled out of the England squad last week with the training ground setback.
But after a week of treatment, Heaton seems certain to resume duties at Southampton on Sunday, along with the other six players on international duty.
Boss Sean Dyche confirmed: “Tom has a niggly calf injury, but we don’t think it’s too serious and we’ll know more on Saturday. He seems ok at the moment, so we are pretty confident with that.
“The rest of the lads came back in good shape and the extra day before the game has been a benefit, as it allows them a day or two extra break.
“People forget that when they are away on international duty they don’t get a break, or see their families.”
There was further good news on the injury front, with striker Ashley Barnes now back in full training after a niggly hamstring injury that has ruled him out since pre-season.
Dyche told Clarets Player HD: “Ashley is feeling all-clear at the minute and that’s an important thing.
“He was at the minor end of an injury and his general fitness has been good. He just couldn’t shake it off, but in the last week or so he has been back in training with us on the grass.
“He’s feeling stronger and better with himself and then, of course, building into next week we’ll see if we can get him some game time in as Development game, then once he’s ready
we’ll look at it again.
“He’s not ready for us yet and not ready to be considered, but he is certainly showing good signs of getting back on track.”