BEIJING — The New York Yankees and the Seattle Mariners have each signed two Chinese players, and there may be more to come.

The Yankees signed two 19-year-old players Monday — left-handed pitcher Kai Liu and catcher Zhenwang Zhang. On Wednesday, the Mariners added catcher Wei Wang and infielder-outfielder Yu Bingjia.

All four signed minor league contracts, becoming the first players from China to join major league organizations.

"I think more will be signing but I don't know if more are pending," said Jim Small, Major League Baseball's vice president for Asia. "But over the course of the next few years more will sign."

Like other American-based games, MLB is trying to break through in China, which has 1.3 billion people and a growing middle class. The NBA has Yao Ming, and MLB would like to discover his baseball equivalent.

Major league teams may play spring training games next year in Beijing, using the baseball venue for next year's Olympics.

It's unclear if the four have a chance to become China's first major league players, but that day is getting nearer, Small said.

"It's very important for the development of baseball in China for players to go and play against the best in the world," Small said. "Playing for any minor league team is important and it will increase their skill level.

"But in and of itself, signing players in not enough," Small added. "For the long-term development of baseball in China it needs to be a multifaceted approach, which would include grass-roots programs."

Baseball has been played in China for more than 100 years, but the game has little following and almost no TV exposure. The only professional league is the six-team China Baseball League, which plays a short schedule and draws a few hundred fans per game.