Union center back Richie Marquez saw his first Major League Soccer action earlier this season against Toronto, coming in as an injury replacement for Michael Lahoud on May 2. He has been hard to get out of the lineup ever since.

Since his debut, Marquez, 23, has started nine of the last 10 games.

"I definitely feel a lot more confident now," said Marquez, the 44th overall choice in the 2014 MLS SuperDraft out of the University of Redlands in California.

The Union (6-10-4) must stop Toronto forward Sebastian Giovinco, who scored the lone goal on an almost 40-yard free kick in a 1-0 win over them May 2.

Giovinco has 11 goals and eight assists. He scored three times and added an assist Sunday in a wild 4-4 draw at New York City FC.

"He is the best attacking player in our league right now," Union coach Jim Curtin said of Giovinco, whose Toronto team is 7-7-3. "It's not one man's job to stop a guy like him."

Still, the 6-foot-2, 185-pound Marquez will certainly be critical in slowing Giovinco down. Fellow center back Maurice Edu must sit out the game because of yellow card accumulation. Ethan White is expected to start in his place.

"I think I am ready for a challenge," said Marquez, who has been strong in the air. "I know it will be a challenge."

A first: free agency

The MLS Players Union's agreement with MLS, which was announced in early March, has been ratified. The agreement runs though the 2019 season.

Among the highlights:

For the first time, free agency will exist for out-of-contract players who are 28 years old with at least eight years of MLS service and are below the maximum salary level. They will be able to choose their MLS teams, with certain salary limits.

The salary budget, which is approximately $3.49 million this year, will increase roughly 5 percent each year, which will take it to $4.24 million in 2019.

MLS Union at Toronto FC


When: Saturday at 4 p.m. TV: Comcast SportsNet.

Union on the road: 1-6-2. Toronto at home: 3-2-1.

Goals: Union, 25; Toronto, 26.

Goals against: Union, 32; Toronto, 27.

This season: Toronto beat the Union, 1-0, May 2 at PPL Park.

Last MLS game: The Union beat the Portland Timbers, 3-0, Saturday at PPL Park. Toronto and New York City FC played to a 4-4 draw Sunday.

Outlook: When Canada was eliminated in the Gold Cup after a scoreless draw with Costa Rica, Toronto (7-7-3) got three players back for this weekend: midfielder Jonathan Osorio, defender Ashtone Morgan, and keeper Quillan Roberts. . . . Toronto midfielder Michael Bradley will miss the game. He is playing for the U.S team in the Gold Cup. Returning is dangerous forward Jozy Altidore, who was replaced on the U.S. Gold Cup team. Altidore has six goals in 12 games. . . . Toronto's Sebastian Giovinco is among the most dangerous players in MLS, with 11 goals and eight assists. . . . C.J. Sapong leads the Union (6-10-4) with six goals in 14 games.

- Marc Narducci