The lights were bright at Fenway Park when Addison Reed made his Red Sox debut last Tuesday night and a dangerous Cleveland lineup waited in the opposing dugout.

Carlos Santana welcomed Reed to the American League with a home run on the fifth pitch he threw.

All signs point to better things in the future.

Reed was drafted by the Chicago White Sox as a 21-year-old in 2010. He shot right to the majors at the end of 2011, pitching well enough in six games to earn a regular bullpen spot in 2012. In two full seasons with Chicago, he struck out almost exactly a batter per inning and kept a 4.20 earned run average.

In December 2013, Reed was traded to the Arizona Diamondbacks. The National League boosted his strikeout rate, but pitching at Chase Field didn’t help Reed keep the ball in the park, as he surrendered 11 home runs en route to a 4.25 ERA.

In 2015, Reed kept the longballs in check and pitched well enough to be swapped to the Mets at the trade deadline for two prospects. That gave him his first taste of the postseason, where he served capably as a setup man until the 12th inning of Game Five of the World Series, in which the Kansas City Royals tagged him for five runs to take the championship.

Reed’s best season yet was 2016, when he struck out 10.55 batters per nine innings and maintained a shiny 1.97 ERA, also making major strides in control- he walked just 13 hitters in 77.2 innings pitched.

That control carried into 2017, Reed’s age-28 season, in which he’s walked just six batters in his first 52 innings.

Boston’s bullpen was a great strength as it surged to the top of the AL East. As a unit, the Red Sox’ 2.96 ERA is second only to Cleveland in all of baseball. Only five AL bullpens strike out more batters (9.27 per nine innings), two yield fewer walks (2.99 per nine) and two surrender fewer homers (.88 per nine). Red Sox relievers have also stranded an impressive 80.1 percent of opposing baserunners, easily the best figure in the league.

Much of that success, though, is the result of Craig Kimbrel’s dominance. Take away his absurd 16.39 strikeouts per nine, great control and stinginess with the longball and the Red Sox bullpen is more average than great. That’s exactly what happened in July, when Kimbrel served up a pair of game-tying homers, Joe Kelly hit the disabled list and Red Sox relievers blew six saves.

Kimbrel’s sudden ineffectiveness, along with an injury to Joe Kelly, whose 1.49 ERA had been a welcome surprise, made Boston’s solid bullpen feel a little shaky. Matt Barnes, whose numbers have been great all season, started to bend under the pressure of a heavy innings load, finally blowing up in a disastrous eighth inning against the Royals the night before the trade deadline.

That was enough to convince general manager Dave Dombrowski to surrender two lower-level prospects to bring in Reed, presumably to work the eighth inning, at least until Kelly returns.

Since giving up that home run to the first batter he faced in Boston, Reed has thrown three shutout innings, striking out three, walking none and giving up just one hit. Manager John Farrell used him in the seventh inning in both outings after the homer, perhaps wanting to keep him away from pressure until he’s a little more comfortable under those bright Fenway lights.

For as great as the Red Sox bullpen has been in 2017, fans haven’t exactly breathed easy in the late innings of close games. This has little to do with the performance of the relievers and much to do with the margins they’ve been asked to protect. Boston’s offense, dominant just a year ago, has been below average this season, so the bullpen has been handed a lot more one-run leads than three-run leads,and 12 games have gone to extra innings, including two July marathons.

Thanks to those extra-inning games, no American League team has pitched more innings than the Red Sox. Through Saturday, only Boston (1,009.1) and Tampa (1,001) had pitched at least a thousand innings, with the last-place White Sox having thrown just 946 (it helps when the other team rarely has to bat in the bottom of the ninth). A team can never have too much pitching and a quality reliever like Addison Reed can make a big difference.

Unless the Red Sox’ offense turns a corner, the key to the team’s success this fall will be winning more close games with dominant pitching, and an imposing spotlight will shine on the late-inning relievers. If Kimbrel can regain his early-season form, Kelly can return to health and Addison Reed can keep pitching like a star, the Red Sox are in great shape to win the division.

Bryan O’Connor lives in Cumberland with his wife and two baseball-loving kids. Follow him on Twitter @replevel.