FORT MYERS, Fla. — When Major League Baseball negotiated a new collective bargaining agreement with the Players Association, one of the changes included shortening the 15-day disabled list to 10 days.

According to Red Sox manager John Farrell, MLB will require teams to provide more extensive proof of injuries to ensure the rules are not being abused to manipulate the roster.

“With it just being 10 days, I think the DL will be scrutinized even greater to try and control that,’’ Farrell said Friday. “I think there’s going be doctor documentation required for every move that’s made to the DL.’’

With a 10-day DL, a team could drop a starting pitcher from its roster knowing he would miss only one game, particularly if there is a scheduled day off for the team during those 10 days.

To use the Red Sox as an example, they will want to control the innings of No. 5 starter Drew Pomeranz, who has never worked more than 170⅔ innings in a season and ended last season with elbow pain.

Putting Pomeranz on the disabled list around a day off would allow the Sox to add a relief pitcher or position player for the short term.

A shorter DL also could encourage teams with a tired bullpen to make a move, particularly if it lacks relievers with minor league options.

Teams also will be able to backdate a disabled list stint by only three days — instead of back to the last game a player appeared in. In previous years, the Red Sox often waited 5-7 days before making a DL decision, particularly for prominent players.

“It’s another way of minimizing the manipulation, or the potential of it,’’ Farrell said.

Three cuts made

Righthander Kyle Martin and lefthander Luis Ysla were optioned to Triple A Pawtucket. Righthander Marcus Walden was reassigned to minor league camp. All three are relievers. The Sox now have 49 players in camp.

Martin will be an option when the Sox need relief help during the season.

“Like the way he attacks lefthanders,’’ Farrell said. “His changeup is his second-best pitch, so that gives him the equipment to attack lefties.’’

Farrell also mentioned righthanders Jamie Callahan and Ben Taylor as relievers who have made a positive impression on the coaching staff.

They’re needed

Farrell called the development of Triple A lefthanders Brian Johnson and Henry Owens “paramount,’’ given the lack of starter depth in the highest levels of the minor leagues.

Owens, who was optioned to Pawtucket Tuesday, is working on a simplified delivery that starts with a smaller step. The hope is that will aid in his command.

“I wouldn’t think this is a huge adjustment,’’ Farrell said.

Owens averaged 5.7 walks per nine innings last season, counting his time in the majors. He walked 12 over 7⅓ innings in four spring training games.

Infield options

The coaching staff has been impressed with Steve Selsky, a 27-year-old outfielder and first baseman claimed off waivers from the Cincinnati Reds in January. The plan is to introduce him to third base and increase his versatility.

Selsky, a righthanded hitter, has a career .838 OPS in the minors and last season had an .810 OPS for the Reds in 24 games.

Brock Holt is the team’s primary backup at second base, third base, and shortstop. But he’s not the only solution. Marco Hernandez and Deven Marrero have played well in camp.

“It probably starts there,’’ said Farrell. “But there would be discussion that would surround it. If [ Xander Bogaerts] were to be missed for any length of time, the discussion is going to center around Marrero and Hernandez.

“If something unforeseen happens at third base, Marco Hernandez is swinging the bat very good. He continues to grow. You can make the claim that he could be an everyday player. We’re fortunate we have options to discuss rather than just default to one.’’

Abad is not bad

Lefthanded reliever Fernando Abad picked up three big outs for the Dominican Republic in its 3-0 victory against Venezuela Thursday night in the World Baseball Classic. With two on and one out in a scoreless game, Abad relieved Edinson Volquez in the fifth inning and got Ender Inciarte to ground into a double play. He then struck out Rougned Odor to start the sixth inning before coming out. Abad has appeared in three WBC games, throwing 2⅓ scoreless innings . . . Bogaerts and the Netherlands have a game against the Diamondbacks Saturday. The Dutch play their next WBC game Monday at Dodger Stadium.

Peter Abraham can be reached at pabraham@globe.com. Follow him on Twitter @PeteAbe.