Sources -- MLB to enforce obstruction rule around bases - ESPN

Major League Baseball intends to strictly enforce the obstruction rule around the bases this season, instructing umpires to be more diligent in calling the infraction, sources tell ESPN.

The league is holding a videoconference call with managers on Wednesday to inform teams.

Obstruction is defined as the act of a fielder who, while not in possession of the ball and not in the act of fielding the ball, impedes the progress of any runner. The league is focused on the latter part of the rule as it believes infielders are blocking runners' paths to the bag under the guise of fielding the ball from a teammate.

The enhanced enforcement of the rule, which is already on the books, will mostly impact plays around second and third base. The most common infraction is when a middle infielder puts his lower leg on the ground to block the runner's path to second, sometimes leading to hand or ankle injuries depending on how a runner slides. A common infraction at third base involves an infielder moving up the line to block a runner's path as he receives the ball from an outfielder.

Umpires have been instructed to call the runner safe due to obstruction unless the infielder must move into the path of the runner to receive the ball.

In the past, players would police themselves, going into a bag with spikes up or even just blowing up an infielder who was blocking his path. Those acts are frowned upon in today's game, which has led to infielders taking more liberties with blocking a base.

The league is instructing teams to tell their players it is OK to straddle the bag or stand in front or behind it, but not to go to a knee or block the path of the runner unless moving to receive the ball. The call is a judgment one that is not