"Just because of precaution, we didn't want to rush it - there was no point in doing that. I'm totally recovered now, training with the team as normal and looking forward. I can't wait to play again.
"It wasn't that nice because my holidays were in the same time as my operation. But after three years without having a proper holiday, I did rest a little bit more this season."
Though not fully involved with his teammates over the last few weeks, Reina has been keeping an eye on activity across the transfer market.
Liverpool have acquired the services Alexander Doni, Charlie Adam, Jordan Henderson and Stewart Downing - good business, according to our Spanish custodian.
"I think we have shown our ambitions during the window," he said. "The rest of the teams did the same and it's going to be tough to compete against them, but we are optimistic, and the season can go really well for us."
Another Liverpool player not involved so far in pre-season is Luis Suarez, who collected player of the tournament when Uruguay won a record 15th South American title last weekend.
Reina added: "It's a great moment and I was happy texting him congratulating him, because he deserved that. And it can be really good for his confidence and the team's confidence at the same time.
"As we saw the last six months of last season, he is a top, top player, and among the best strikers in the world. He will show that, he will be a fantastic player for us."