He played college football at Florida, and signed with the Oakland Raiders as an undrafted free agent in 2018 before joining the Chicago Bears the following year.

His father, Eddy Sr., came to the United States from Cuba at the age of nine during the Mariel boatlift of 1980 and later had a professional soccer career with the Fort Lauderdale Strikers of the ASL/APSL.

[4] Piñeiro signed with Florida Atlantic on a scholarship to play soccer but academic issues prevented him from attending.

Out of hundreds of kickers, Alabama coach Nick Saban narrowed his scholarship offers to Chris Salek and Piñeiro.

[11] During his final year at Florida, Piñeiro had the best field goal percentage in the nation, making 17 out of 18 attempts for a 94.4% conversion rate.

[12][13] His career conversion rate of 88.4% (38-for-43) ranks first in school history (minimum 35 attempts), surpassing Bobby Raymond (who made 43 of 49 kicks, or 87.8%, in 1983 and 1984).

[18] The tryout was orchestrated by coach Matt Nagy to find a new kicker in the wake of the Bears' "Double-Doink" loss against the Philadelphia Eagles in the playoffs, when Parkey missed the game-winning field goal when the ball hit the upright and then bounced off the crossbar before falling to the ground.

[21] In the first game of the 2019 regular season against the Green Bay Packers, Piñeiro made his first NFL field goal on a 38-yard kick.

[22] During Week 2, Piñeiro kicked a game-winning 53-yard field goal as time expired to give the Bears a 16–14 win over the Denver Broncos.

In the season finale against the Minnesota Vikings, he was perfect on one extra point and four field goal attempts, including the game-winning 22-yarder to secure the 21–19 victory.

[33] After the 2019 season, both coach Matt Nagy and general manager Ryan Pace expressed confidence that Piñeiro would be the team's kicker in 2020.

[39] However, Piñeiro struggled with a groin injury that prevented him from kicking in training camp and resulted in him being placed on injured reserve on September 8.

[51] On December 1, he fell out of first-place all the way to third, going 3-for-5 in Carolina's game against Tampa Bay and falling to 88.525%, behind both Tucker and Kansas City's Harrison Butker who became the new leader while on injured reserve, with a percentage of 89.212%.

Before the Bears’ October 2019 game against the Raiders in London, Piñeiro received a glass sculpture as a gift from Nicaragua’s ambassador to the United Kingdom.