Central America and the winter leagues

Major league players will be allowed to compete in winter leagues this season after Major League Baseball and the players' association reached an agreement on restrictions that will limit pitchers' participation but loosen limitations on position players, sources with knowledge of the deal told Yahoo Sports.

Terse negotiations between the parties in recent months stoked fears that players on teams' 40-man rosters – the stars and staples of leagues in the Dominican Republic, Venezuela, Puerto Rico and Mexico – would be barred from playing this year. The five-year agreement, reached Friday and ratified by the Caribbean Confederation on Saturday, will allow players to report within a week.

MLB aimed to keep pitchers – particularly young ones – from taxing their arms after significant workloads, while the union wanted to allow players as much leeway as possible to play if they desire. In the past, teams have been allowed to restrict players based on "extreme fatigue" and "physical incapacity" rules that related to player usage and injuries the previous season. 

Starting this year, Double-A starting pitchers – those on the 40-man roster with a majority of their time spent at Double-A – cannot participate in winter ball if they threw 140 or more innings. The previous threshold was 155. Similarly, Double-A relievers cannot have appeared in more than 45 games, while in years past it was 55.

Pitchers also are ineligible if their workload in games or innings grew 25 percent over the prior season. The caveats: They must've reached 60 percent of the games-or-innings threshold the previous season, and players switching from the rotation to the bullpen or vice versa don't count.

Instead of a 502-plate appearance threshold for major league position players, those with up to 552 now can play winter ball. Moreover, the past procedure of declaring a "physical incapacity" – teams simply had to provide documentation – now has strict rules. Unless a player finishes the season on the disabled list or spent 60 days on the DL (including 15 over the final 60 days of the season), a team cannot declare him physically incapable. The exception is pitchers who have undergone major surgery in the previous 18 months.

Off-field improvements for players include the requirement of MLB-certified trainers, higher-quality equipment and increased standards for fields, clubhouses and bathrooms, with a compliance program to address issues.

The Venezuelan Winter League and Mexican Pacific League began play this week. The biggest and best league, the Dominican Winter League, starts Friday, and opening day for the Puerto Rican League is Nov. 1. The league's winners will meet in the Caribbean Series, scheduled to be held on Margarita Island, Venezuela, in February 2014.