"Tourists" for visiting sports team

In news about English and "Commonwealth" team sports (e.g., rugby, cricket), I occasionally hear the visiting team being referred to as "tourists" (e.g., "the tourists won the match ..."). This usage is listed in very few dictionaries, probably because it is almost unknown in North America, and those are the sources I have available.

I'm wondering what the connotations of that usage are. Does it simply mean "one who tours" in the very original sense of the word, or does it have sarcastic undertones, likening the visiting team to sightseers?

Also, what constitutes a tour? If an English football team plays a match in another English town or, say, in Italy, are they also "tourists"?

I would say that the term is predominantly used for cricket. Perhaps because of all the major international sports the participating countries in the main are very dispersed (in particular from a British perspective). So cricketing teams would traditionally have to travel long distances for an international fixture. And once you have made a long trip it would make sense to arrange a series of fixtures (a "tour") rather than a one-off.

There is no sarcastic intent.

If an English football team plays a one-off match in another English town or a nearby country then that is never referred to as a tour because they'll return home straight after the match.

A visitor to a country is often known as a tourist and it is in this sense that a sports team is called a tourist team, it means the same as a visiting team.

Tours are a specific form of sport organisation. A team will travel a long distance - usually to another country, but for very local teams, perhaps just a long distance in their own country - and then stay there for many days, and play a series of matches, perhaps all against the same opponent, perhaps against many different opponents, before returning home.

They are common with international teams in rugby union and cricket, and most professional association football teams will have a pre-season tour where they travel to another country to play exhibition matches. The USA and the Far East (Singapore, Malaysia, Thailand, Japan, China, Taiwan in particular) are common places for pre-season tours to go.

There is a distinction between a tour and a tournament (such as the Football World Cup), but I'm having trouble expressing it clearly; perhaps someone will clarify that in the comments.

A cricket tour will involve the representative team of one country travelling to another, usually for two to four months, and playing a number of matches against various first-class (the highest level below international) teams as a warm-up, then playing a formal series of Test matches against the representative team of the country they are in. The "touring team" or "tourists" stay in the country they are playing against for the whole duration of the tour.

A typical example might be the Australian team travelling to England.