Major League Soccer and the United Soccer League announced a historic agreement last month, linking two of the biggest soccer leagues in North America.

Carolina Challenge Cup

Today at Blackbaud Stadium

Vancouver vs. Houston, 5 p.m.

Chicago vs. Charleston, 7:15 p.m.

Tickets: 971-4625

The initial agreement includes interleague play between USL Pro and MLS Reserve League teams and the establishment of several team affiliations this season. The Charleston Battery will play two games against a reserve team from the Houston Dynamo this summer.

The coaches from the three MLS teams in town for this week’s Carolina Challenge Cup agreed it was a long overdue move for the two leagues.

The question now becomes, what’s next?

Will the USL Pro division became an official minor league for MLS, similar to the minor league systems in professional baseball and hockey? Four USL Pro teams already have affiliation agreements in place — Orlando and Kansas City, Richmond and D.C. United, Rochester and New England, and Harrisburg and Philadelphia.

Or will MLS reserve teams became a part of USL Pro division?

The most likely scenario for the near future is a combination of both, according to Houston Dynamo coach Dominic Kinnear. Some MLS teams will have affiliations, while others will choose to field reserve teams in the USL Pro division.

“I think it’s really too early to say which way this thing will go. I think for the next couple of years you’ll see both,” Kinnear said. “I think ultimately you’d like to have an affiliation where MLS teams are using the USL Pro as stepping stone for players getting to the MLS.”

Not surprisingly, money will play a huge factor in the ultimate fate of the agreement between the two leagues. MLS clubs that can afford it will continue to field reserve teams with their players under the direct supervision of their coaching staffs. Others will opt for the more cost efficient minor league affiliation and loan players to the USL Pro.

“The coaching staffs will have to be in sync with each other,” Kinnear said. “They have to be thinking the same thing and playing the same way, but I think that can be accomplished.”

The need for some kind of minor league for the MLS has been painfully apparent for some time. One of the biggest issues holding American soccer back is the country’s lack of developmental leagues, especially at the professional level. Former Battery striker Tom Heinemann, who has played for Columbus and Vancouver, contends that he wouldn’t be in the MLS today if he had not played in the USL.

“There’s been so much division in American soccer over the last 10 to 15 years, it’s nice to see everyone finally start to get together,” Heinemann said. “I think this is a great stepping-stone for USL and the MLS. I think this is going to help develop players, which is something that has been lacking in the United States and in North America.”

Chicago coach Rank Klopas said getting games for young players is crucial for their development. One of the problems with the MLS reserve games is that there’s nothing at stake.

“It’s very important for guys that don’t play on a regular basis to get a chance to play in meaningful games against quality opponents,” Klopas said. “I’m hoping that this new relationship will provide that. As a player, you need to be playing. There’s no substitute for game action. You get better with more experience and you stay sharper.”

The second round of the Carolina Challenge Cup is tonight with Vancouver taking on Houston (5 p.m.) and the Battery facing Chicago (7:15 p.m.) at Blackbaud Stadium.