Ki Sung-yueng's confident he'll be close to full fitness for the start of the Premier League season.
The midfielder joined Newcastle United on a free transfer this week after being released by relegated Swansea City.
Ki missed South Korea's final World Cup group game against Germany with a calf injury.
However, the problem is not serious, and Ki believes he will be able to hit the ground running when he returns to Tyneside later this month ahead of the club's season-opener against Tottenham Hotspur on August 11.
"It's not a serious problem," said the 29-year-old, who returned to his homeland for a holiday after completing the move.
"It's not a tear, just a little strain. I got knocked from Mexico's players at the end of the game. I couldn't play because of the short period until the Germany game. Now I can train. There's not a problem.
"I need some rest now to recover from the national team, because I had one month preparation after the season.
"When I come back from holidays, I have to be ready 100% mentally and physically. I will do some work in Korea while on holiday. I have two weeks to prepare for the first game. Maybe I can't be 100%, but I should be almost 100%."
Ki's move to Newcastle was completed inside two days after South Korea were eliminated from the World Cup.
Asked about the move, Ki said: "It took two days. I'm thankful to the club for giving me the opportunity to play for such a great club. I'm really looking forward to it.
"There was no hesitation when I had a first offer from the club. It was very quick decision. I know this club has big ambitions and I know all the players I've played against."