FORT MYERS, Fla. -- After a productive weekend of collaboration between the Red Sox and slugger J.D. Martinez, the sides completed the five-year, $110 million contract that was agreed upon last week, the club announced Monday morning.
A news conference was held at JetBlue Park to formally introduce Martinez, one week after he and the Red Sox agreed to terms on a deal that includes opt-outs after the second and third seasons, according to sources.
Martinez came to Fort Myers on Wednesday for a physical. The Red Sox determined from the physical that Martinez is fully healthy for 2018. However, they spotted an issue that could be of concern at some point over the length of the contract and sought some other medical opinions.
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From there, the Red Sox and agent Scott Boras, who represents Martinez, worked through the situation all weekend cooperatively and professionally, as both sides just wanted to protect themselves with additional contract language.
Martinez had a sprained Lisfranc ligament in his right foot last year and a right elbow injury in 2016. It is unknown what the precise medical issue is that delayed the formalization of the much-anticipated union between Boston and Martinez.
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The Red Sox continued to go about their business without Martinez on Sunday, defeating the Orioles, 7-1, in a Grapefruit League game.
Manager Alex Cora will be excited to greet Martinez once he arrives, but he said Sunday morning he's too consumed with other things to be stressed about the delay in officially adding the new slugger.
Martinez will wear his familiar No. 28, thanks to Cora, who gave up that number earlier this week and switched to 20.

Red Sox Nation has been abuzz all week with the news of Martinez's coming.
The right-handed-hitting masher wields the type of pure power bat the Red Sox missed so much in 2017 -- David Ortiz's first in retirement. Martinez roped 45 homers last year in just 432 at-bats. That power will be a welcome addition to a Boston team that finished last in the American League with 168 homers last year.
It will be interesting to see if Martinez, an all-fields hitter, tries to pull the ball more often at Fenway. He has played just seven games in Boston in his career and made the most of them, going 12-for-27 with two doubles.
An outfielder, Martinez will get a lot of his playing time for the Red Sox at designated hitter. Boston has a strong outfield of Andrew Benintendi, Jackie Bradley Jr. and Mookie Betts. Hanley Ramirez will become the team's primary first baseman, sharing time there with Mitch Moreland.

With strong table-setters like Betts and Benintendi slotted in for the top two spots in the lineup and Ramirez likely to hit third, Martinez should have no problem breaking the personal best of 104 RBIs he set last year.
The Red Sox are excited about adding the 30-year-old veteran to their impressive young nucleus of Betts, Benintendi, Xander Bogaerts, Rafael Devers and Bradley.
It was Red Sox president of baseball operations Dave Dombrowski, then the Tigers' general manager, who scooped Martinez up just two days after the Astros released him in March 2014.
In the 520 games since Houston let Martinez go, he has produced a line of .300/.362/.574 with 128 homers and 350 RBIs. He looks forward to continuing that momentum with Boston, where he will be reunited with two former teammates from Detroit -- David Price and Rick Porcello.
Dombrowski established Martinez as his top target as soon as the offseason started and never wavered, even when negotiations slowed.
The Red Sox's patience has been rewarded.