Jozy Altidore, scoring against Seattle in MLS Cup in December, might join his Toronto FC teammates in a showdown with a Liga MX champion this fall. (Nathan Denette/Canadian Press via AP)

MLS and the top Mexican league are in discussions about an annual match between their respective champions, starting as early as this fall, multiple sources told the Insider on Tuesday.

The proposed first meeting would probably take place in mid-September at Toronto’s BMO Field between MLS Cup champion Toronto FC and a Liga MX club, presumably the winner of the Clausura tournament, which will conclude in May. It would be a single match, with no return leg.

Because both teams have league matches scheduled on weekends, the game would almost certainly take place mid-week. Toronto is home Sept. 15 and away Sept. 22, leaving the week open for a visit by a Mexican foe.

The sides have engaged in talks for several months, sources said, and could finalize a deal early this year.

MLS and Mexican teams have clashed many times over the years, almost always as part of CONCACAF tournaments, such as the Champions League. Mexico has dominated that competition, winning 12 consecutive titles, while MLS has placed just two teams in the finals since 2002.

Besides Liga MX’s superior rosters, the dates of the Champions League’s knockout stages have favored Mexico because they are early in the calendar year, when MLS is just starting the season and the Mexicans are more than halfway through their competition.

MLS runs March through October, while Liga MX plays July through November (Apertura) and January through May (Clausura).

The proposed September date would fall late in the MLS campaign and far enough along in the Mexican season that players would be in strong form. However, it’s unclear how seriously the participating clubs would take the one-off game.

Long term, an annual match between the sides could someday pave the way for some greater form of interleague play.

MLS and Mexican soccer have deep business ties: Soccer United Marketing, which is owned by MLS, represents the Mexican soccer federation and stages several national team matches annually at U.S. venues. SUM is also involved in other CONCACAF properties.