The Red Sox added a third starting pitcher since Wednesday night while the Royals filled a void at the designated hitter position and the Mets added depth to their outfield. The last day of the MLB Winter Meetings is in full force.

After offering Justin Masterson a contract earlier this week, the right-hander agreed to a one-year deal on Thursday, according to ESPN's Buster Olney. Masterson will earn $9 million in 2015, writes Bob Nightengale of USA Today. The 29-year-old was drafted by the Red Sox in 2006, where he spent two seasons before being traded to the Cleveland Indians. He spent six seasons there before he was sent to the St. Louis Cardinals before this year's trade deadline.

He'll now return to Boston and likely join the back end of the rotation. Masterson's career numbers consist of a 60-72 record with a 4.24 ERA and 1.39 WHIP in 240 games (175 starts). He was an All-Star in 2013 after going 14-10 with a 3.45 ERA and 1.20 WHIP in 32 games (29 starts) with the Indians.

In Kansas City, the Royals filled the DH vacancy left by Billy Butler and signed Kendrys Morales to a two-year, $17 million contract with incentives that can make the deal worth up to $18.5 million, according to Jeff Passan of Yahoo! Sports and Jon Heyman of CBS Sports. Morales, who made it known he wanted a contract in the three-year, $30 million range, is just one season removed from slashing .277/.336/.449 with 23 home runs and 80 RBIs in Seattle. He signed with the Twins last offseason and was then traded back to the Mariners. He made his 2014 debut on June 9 and batted .218/.274/.338 with eight home runs and 42 RBIs in 98 games.

The New York Mets orchestrated a much more low key signing and added outfielder John Mayberry Jr. on a one-year deal worth $1.45 million, reports Joel Sherman of the New York Post. The move adds depth to the outfield, which consists of Curtis Granderson, Juan Lagares and Michael Cuddyer. Mayberry Jr. owns a career stat line of .241/.305/.429 to go along with 53 home runs and 171 RBIs in 515 career games. The 30-year-old was traded from the Phillies to the Blue Jays in September and was non-tendered by Toronto last week.

There should be more to come by the end of today.