Lionel Messi said Tuesday his leg injury was "getting better" but the World Cup-winning captain could not guarantee he would be fit to play in Inter Miami's pre-season friendly in Japan this week.

Two days ago, furious fans in Hong Kong booed Messi and club co-owner David Beckham, shouting "Refund", after the Argentina great failed to take the field for a sold-out friendly.

"I don't know if I can (play) or not but I feel a lot better and really want to do it," eight-time Ballon d'Or winner Messi told reporters ahead of their match against Japanese champions Vissel Kobe on Wednesday.

"This afternoon we're going to practise, we'll try again. I have a good feeling, compared to how I was."

Excitement has been building for the friendly at Tokyo's National Stadium, with Inter Miami's pink colours adorning parts of the city's trendy Shibuya district.

Tickets for the Japan leg of the US Major League Soccer (MLS) club's globe-trotting pre-season tour are costing between 10,000 yen ($68) and 200,000 yen ($1,346) with "special experience" packages priced even higher.

A crowd of nearly 40,000 in Hong Kong who paid for similarly expensive tickets were involved in angry scenes, jeering and giving thumbs-down signs, after Messi stayed rooted to the bench during their 4-1 win against a local select XI.

The Hong Kong government demanded an explanation from the match's organisers.

"It was really bad luck that I couldn't play in Hong Kong," Messi said.

"Unfortunately this happens in football, in any game it can happen that you can't play," he added.

"I always want to participate, I want to play, especially in these games where we travel so far and people want to see our games. I hope we can return and play a game in Hong Kong."

The furore came after the 36-year-old Messi came on as a substitute six minutes from the end of Miami's previous match in Saudi Arabia last Thursday.

"I played the minutes that I did to see how I felt," he explained. "I later did a MRI scan and it turned out I had an oedema (swelling)."

Miami's win in Hong Kong was their first in five pre-season matches. They drew 0-0 in El Salvador, lost to fellow MLS side FC Dallas and then twice to club sides in Saudi Arabia.

They have one more friendly, at home to Argentina's Newell's Old Boys next week, before the new MLS season starts on February 21.