NEW YORK, N.Y. - Turns out Major League Soccer never had a finalized labour contract for the last five years, a situation players and management hope to rectify following their agreement in principle last week on a new deal through 2019.

The new labour agreement increases minimum salaries but cuts the roster size of each team from 30 to 28. The union says the last few players on each side never saw much time on the field.

Players and the league reached a memorandum of understanding five days before the 2010 season opener but never took the time to draft a full collective bargaining agreement. Management and the union instead operated under the memorandum of understanding they signed, which in labour negotiations lists the modifications the sides agree will be made to their previous contract.

"There were dozens of little things in the conversion that would have been required, and neither side ever took the time to get the other to sit down and actually do it. It was that simple. It wasn't all that important," L. Robert Batterman, the league's lead labour lawyer at Proskauer, told The Associated Press on Wednesday. "This time, to avoid the risk of being in a situation with a CBA from 10 years ago and then two MOUs, we're going straight to the CBA."

The union website still has a link to the 2004-10 agreement, the first in the league's history.

"It's frustrating for all concerned," union head Bob Foose said. As for what the sides agreed to in 2010, he added: "We know. Without the document, everyone else doesn't."

A similar circumstance occurred in Major League Baseball from 1985-89, when teams and players operated under the 1980 labour contract as modified by their 1981 agreement on free-agent compensation and their 1985 MOU. In baseball, the sides couldn't agree on some aspects of what was in the MOU.

Last week's MLS deal, reached two days before the league opener, creates free agency for the first time. Players 28 and older can become free agents if they have eight seasons of MLS service and their contracts have expired. Free agents earning under $100,000 this year are capped at 125 per cent for 2016, with the limit lowering to 120 per cent for those making $100,000-$200,000 this year and 115 per cent for those earning more than $200,000.

Foose estimated 12.5 per cent of the player pool will meet the free-agency requirements this year and said the provision will have a wider reach because it may spark new contracts that prevent players from going free.

"The impact it has on players' renegotiations with their current teams is changed dramatically," Foose said. "To the extent that the player pool has a perception of how an individual team treats players, there could be a real cost to that on the negative and a real benefit to that on the positive."

Foose said the union estimated the average salary for the first 20 roster spots on each team, not including high-priced designated players, will rise from $126,000 last year to $186,000 by 2019.

The sides agreed to cut two players from each roster due to the elimination of the reserve league. MLS teams this year will use franchises in the third-tier United Soccer League for player development

"As we looked at those 29th and 30th spots, they really weren't going to come with any ability to play in a game," Foose said.

The minimum salary will rise from $48,500 to $60,000 for the first 24 roster spots on each team and from $36,500 to $50,000 for the remaining players, with a requirement those at the lower figure must be under 25 years old.

Foose said a key to negotiations came on the final day, when the league dropped its demand for an eight-year contract. He understands some on his side hoped for players to gain more.

"Expectations on our side were very high, and that to me is a healthy thing, and that also has evolved over time. When we started the union, I'm not sure anybody had any expectations," he said. "I certainly think that there is very solid economic progress in this deal and that's a good thing. And it was done at the same time that we are able to crack into free agency for the first time, which was a very significant achievement and not one that came easily."