Base coaches can't cross the lines until batted balls pass them

Updated: February 28, 2008, 5:12 PM ET

NEW YORK -- Base coaches in the big leagues will have to stay inside their boxes this season.

Major League Baseball announced a few rule amendments Thursday, including one that came a season after Double-A coach Mike Coolbaugh was killed by a line drive to the neck.

Starting this year, first- and third-base coaches must not cross the lines toward home plate or the field until batted balls pass them. Only then can they take up other spots to guide runners.

Third-base coaches routinely stand much closer to the plate than the lines permit, trying to get a better look at where outfielders are positioned.

In November, general managers decided big league base coaches must wear protective headgear this year, starting with exhibition games.

Other amendments adopted by the Playing Rules Committee will be tried on an experimental basis in the Class A New York-Penn and Northwest leagues.

Pitchers will have 15 seconds, rather than the previous 12 seconds, to deliver the ball. The time will start when the pitcher gets the ball.

Also, after three or more visits to the mound by a manager or coach without taking out a pitcher, the fourth mound trip will result in a pitcher automatically being pulled.

In addition, only one infielder at a time will be allowed to visit the mound.