Western New York currently does not have a team in Major League Soccer (occasionally considered the fifth major league on the American sporting landscape), although Rochester had been mentioned in the past as a candidate for a new expansion franchise and previously hosted the Rochester Lancers in MLS's predecessor, the NASL. The speculation of Rochester getting an MLS team was due to the relative success of the Rochester Rhinos. However, in recent years the Rhinos have seen a downturn in attendance due to a number of factors. Such speculation has decreased in the 21st century, in part because of MLS's refusal to put teams in metropolitan areas without any other major league teams and greatly increased competition for MLS expansion franchises. The Rhinos are something of a regional team in Western New York, though at nowhere near the popularity of the Bills or Sabres. The Rhinos are best known as being the only non-MLS team to win the US Open Cup since that competition was opened to MLS teams.