Carroll has been sidelined since the final day of last season with a heel injury.
"I've been working hard. I've been away to Germany with the lads and keeping myself as fit as I can with the work I can do with my heel still being sore," Carroll told West Ham TV. "It's been tough but I've been working hard to be back for the beginning of the season.
"I'm doing a lot of cardiovascular work to keep my fitness up without stressing my heel, which means going on the rowing machine and on the bike and doing all the things I don't like, really! I've been working hard, hopefully I'll be back for the start of the season.
"I couldn't think of anything worse than being injured during pre-season. It's painful to watch everyone else going out and having a laugh and me just doing one-on-one physio work in the gym. It's a nightmare but I've just got to get myself fit and ready.
"I don't like it in the gym, so it makes me push myself that bit harder. I'm dying to get back and kicking a ball again. I can't wait because the last time I kicked a ball was in the final game of last season."