Four of the Twins' brightest prospects were added to the team's 40-man roster on Thursday to shield them from next month's Rule 5 draft. Now the question is: When will they become part of the 25-man roster?

Third baseman Miguel Sano, second baseman and outfielder Eddie Rosario, right-handed starter Alex Meyer and left-hander Jason Wheeler became part of the major-league team on Thursday, the deadline for setting rosters before the Rule 5 draft.

All were easy and obvious choices for the Twins, since they are considered among the best prospects in Minnesota's system. Sano, 21, who has 90 home runs in his minor-league career, is one of the best power-hitting prospects in minor-league baseball, despite missing the 2014 season after elbow surgery. Rosario, 23, is a talented left-handed hitter who recently batted .330 in the Arizona Fall League and helped lead Salt River to the championship.

Meyer, 24, was acquired from Washington for Denard Span and struck out 153 batters in 130 innings last season for Class AAA Rochester. And Wheeler, 24, an eighth-round pick in 2011, posted a 2.67 ERA at Class A Fort Myers and Class AA New Britain last season.

All four players will come to spring training with the Twins and have a chance to make the major-league team, although Meyer is considered the only player expected to do so right away. But all four are likely to be in Minneapolis at some point next season or in 2016.

Players with five seasons of minor-league experience, or four seasons if they were signed after turning 19, are eligible to be drafted by any team if they are not on a 40-man roster.

For the Twins, that means players like Levi Michael, their first-round pick in the 2011 draft, and Sean Gilmartin, a left-hander and former first-rounder acquired in the Ryan Doumit trade last year, can be drafted.

The Twins needed to make no cuts to their roster to add the four players. Their roster now stands at 40.