The 34-year-old Pedroia said Wednesday that he's been doing that in baseball since junior high school.
Pedroia and several teammates were accused of using an Apple Watch to relay signals of opposing catchers. Baseball has no rules against stealing signs, but doesn't allow the use of technology in the endeavor.
On Tuesday, The New York Times reported that the AL East-leading Red Sox admitted to Major League Baseball that they used the watch to relay the signals to Boston players. The allegations were levied by the Yankees to MLB.
Pedroia says players know that stealing signs is part of the game and doesn't understand why there's been such a fuss. Red Sox manager John Farrell says baseball is investigating the claim and has no idea how long it will take.
Red Sox general manager Dave Dombrowski said it was the first time a team he'd worked for had been formally accused of stealing signs.
"I've been in the game for 40 years. I've known of it for 40 years, sign stealing itself," Dombrowski said. "I've known of people that I talk to that played back in the `50's that talked to me about sign stealing, so I do think sign stealing has been taking place for a long time. I will acknowledge that."
This isn't the first time a successful Boston-area sports franchise has been accused of cheating in recent years.
New England Patriots star Tom Brady was suspended four games by NFL Commissioner Roger Goodell after the "Deflategate" investigation concluded the quarterback conspired to use illegally underinflated footballs in the 2015 AFC championship game. The Pats also were docked a first-round draft pick.
Years earlier, the five-time Super Bowl champions were caught videotaping signals being sent in by Jets coaches during a 2007 game — the Patriots lost a first-round pick in the 2008 draft and coach Bill Belichick was fined $500,000 in "Spygate."
The Red Sox hold a narrow lead over the Yankees in the AL East race with a month left in the regular season. The teams don't play again this season.
The Red Sox staged their own impromptu Boston marathon and wearily won it, adding a game to their AL East lead on Tuesday night at Fenway Park.
It was 1:11 a.m. when Mookie Betts led off with a double and Ramirez followed with a bloop single. The AL East leaders ended a three-game losing streak.
"That was a team win right there," Ramirez said. "Sometimes it's not going to be easy. There's a lot of things in our way, but nothing's going to stop us from continuing to where we want to go and what we want to be. We want to be a champion."
About 700 fans stayed until the end to see Boston win the longest game in the majors since July 2016, when Cleveland beat Toronto 2-1 in 19 innings. The Red Sox forced extra innings by rallying for two runs in the bottom of the ninth.
Red Sox first baseman Mitch Moreland was 31 years old when his RBI grounder tied it at 2 — he turned 32 when his birthday came at midnight, and celebrated with a win.