Ortiz was the Most Valuable Player of the 2013 World Series, when he hit .688 against the Cardinals.
The game-tying grand slam Ortiz hit with two outs in the eighth inning in Game 2 of the American League Championship Series is considered one of the most monumental hits in Red Sox history.
Behind Ortiz, the Red Sox have won three World Series championships in the past 10 seasons.
In fact, Ortiz is the first non-Yankee to win as many as three World Series titles since Jim Palmer finished his trifecta with the Orioles in 1983.
Revered in New England and by his teammates for both his production and his presence, Ortiz first stated back in December that he'd like to play at least one year beyond the '14 season.
Big Papi will be roughly a month shy of his 40th birthday when the 2015 season ends.
When Ortiz came to the Red Sox in 2003, it was only after the Minnesota Twins had released him.
All 30 Major League teams could have signed him, but former Red Sox general manager Theo Epstein was able to scoop Ortiz up with a one-year, $1.25 million deal.
The extension is the sixth new deal Ortiz has signed with Boston since that bargain in '03.
In Ortiz's first two months with the Red Sox, he was a platoon player, just like he was for those six years with Minnesota.
But when the Red Sox traded Shea Hillenbrand to the D-backs in May 2003, Ortiz became a full-time player for the first time in his career and proceeded to finish fifth in the race for the AL MVP Award.
Over the past decade, he has easily been the most dominant designated hitter in the game -- and perhaps of all time.
The Red Sox had several meetings with Ortiz's agents this spring, and the sides were close to a new deal a couple of days ago.
This will be Ortiz's 12th season with the Red Sox.
In his first 11 seasons in Boston, Ortiz has compiled 373 homers, 1,191 RBIs and a slash line of .292/.390/.572.
Over the course 1,969 Major League games, Ortiz has 431 homers and 1,429 RBIs.
The regular-season numbers are impressive, but much of Ortiz's legend has been built in October.
In 82 postseason games, Ortiz is a .295 hitter with 17 homers and 60 RBIs, many of the hits coming either in walk-off fashion or with the game on the line.
In the 2004 ALCS against the Yankees, Ortiz drilled a walk-off homer in Game 4 to avoid a sweep. The next day, he looped a single into center in the 14th inning of Game 5 to send the series back to New York, where Boston became the first -- and still only -- team in MLB history to come all the way back from a 3-0 deficit in a postseason series.
Considering that the Red Sox had gone 86 years without a World Series championship, the '04 exploits by Ortiz seemed untouchable.
Then came Boston's unlikely run in 2013, a season after finishing in last place, when Ortiz put on one of the most dominant World Series displays of all time.
Ortiz has struggled in Grapefruit League action this spring, going 2-for-35 with 12 strikeouts. But that hasn't been a concern to Ortiz or the Red Sox.
"I'll be fine," Ortiz said to a small group of reporters. "What else?"
At this stage of Ortiz's career, he admits it's hard for him to generate much adrenaline in Spring Training.
"Spring Training doesn't mean [anything] to me," Ortiz said. "Just intensity [is different], you know. Motivation. I don't know. I just go through Spring Training and whatever. I know what I need to do to be ready for the season. Spring Training is nothing that worries me about anything.
"Like we mentioned the other day, we're not concerned with him," said Red Sox manager John Farrell. "David's going to be fine, just when you watch the bat speed, seeing the ball come off the bat in BP. He's going to get more ABs [Monday], probably take the day off the next day and then after that we'll run it out through the end of camp. His timing is going to be fine."