"I enjoyed my time with Mariners, but I just want to play," Carp said from his home near Anaheim, Calif. "I'm just thankful for the opportunity. You talk about the Red Sox and their tradition, to get a chance to put my name on the list of guys who've played there means a lot. Hopefully I can live up to the expectations I have for myself."
Carp opened last season as Seattle's starting left fielder, but he sprained his throwing shoulder diving for a ball on Opening Day in Tokyo, wound up missing considerable time and hit just .213 with five home runs and 20 RBIs in 59 games on the year.
In four seasons in Seattle, he batted .255 with 18 homers and 71 RBIs, including a 20-game hitting streak after getting called up in the second half of 2011.
He finished that year batting .276 with 12 home runs and 46 RBIs and seemed to have found a place in the Mariners' lineup, but last year's injuries -- which also included a strained groin muscle later in the year -- hampered his efforts.
When the Mariners acquired Kendrys Morales, Michael Morse and Raul Ibanez over the offseason, Carp's chances of finding playing time diminished. He was out of Minor League options and would have had to make the final 25-man roster or be exposed to waivers, so he was designated for assignment on Feb. 12 to make room on the 40-man roster for left-hander Joe Saunders.
"I looked at all the roster moves and acquisitions, and they didn't really have a place," Carp said. "I thought maybe I'd come to camp and have something happen, but I've been a casualty of roster space before, so I understand. I just want to make the most of this new opportunity."
With the Red Sox, Carp will compete with non-roster invitee Lyle Overbay to be the backup first baseman behind Mike Napoli. Manager John Farrell told reporters in Boston that he likes Carp's plate approach and that his defensive flexibility is helpful.
"It increases the competition, particularly at first and left field," Farrell said. "We've been able to add a talented player to camp here -- someone that we've had conversations about throughout the course of the offseason. Finally he became available. [He's] another left-handed hitter that has that versatility on the defensive side."
Carp was originally acquired by Seattle from the Mets in December 2008, as part of a three-team, 12-player trade.
"I grew up and became a man there," Carp said. "I'll miss it up there. I loved the Pacific Northwest and made a lot of great friends. I remember being there for the Caravan this offseason and I told my wife this might be our last time there, so we should soak it up."
Turns out he was right, though he'd already checked the schedule by Wednesday afternoon to see that the Red Sox visit Seattle for four days in July.
First, of course, he has to find a spot on Boston's roster. And as much as he'll miss Seattle, the idea of playing in Fenway Park has plenty of appeal.
"I've gotten goose bumps just walking up there when we played there," he said. "To have that be a home field now and sit in the dugout where Ted Williams and all those greats have been is pretty awesome. I'm just anxious to get out there and get started."
Carp was scheduled to fly to Fort Myers, Fla., on Thursday morning.
"We're very grateful that [Seattle general manager] Jack Zduriencik worked with Mike to put him in a good situation," said Carp's agent, Tom O'Connell. "He's just looking forward to starting the next chapter of his career."