Stevens played a few games with the Penguins in the 1987–88 NHL season, then spent the 1988–89 NHL season jumping back and forth between the National Hockey League (NHL) and the Muskegon Lumberjacks of the International Hockey League (IHL). Starting with the 1989–90 NHL season, Stevens became one of the top left wingers and power forwards in the league. He had four consecutive seasons of at least 40 goals and 80 points from 1990 to 1994 and surpassed 50 goals and 100 points in 1991–92 and 1992–93. In the 1991–92 NHL season, Stevens scored 2 points more than Wayne Gretzky (then in his 13th season), becoming only the third person in NHL history to outscore Gretzky in the regular season, though he still finished second in points to teammate Mario Lemieux. His 123 points that year also set a record for the most points by an American-born player and a left wing in one season. The 55 goals he scored the following year tied him with Jimmy Carson for most goals in a single NHL season by a United States-born player. That record would stand for another 29 years before being broken by Auston Matthews on April 7, 2022.[4] During the Pittsburgh Penguins' back-to-back Stanley Cup seasons of 1990–91 and 1991–92, Stevens was the only Penguin to play in every regular season and playoff game. He is also one of four NHL players to have accumulated more than 50 goals and at least 200 PIM in a season, the others are Keith Tkachuk, Brendan Shanahan and Gary Roberts. His 17 goals during the 1990–91 playoffs are tied for fourth all-time (only Jari Kurri and Reggie Leach with 19 and Joe Sakic with 18 have surpassed that mark). He scored 13 more in the 1991–92 postseason.
On May 21, 1992, during game three of the Prince of Wales Conference final against the Boston Bruins, Stevens became the 25th player in NHL history to score three goals in a single playoff period. Scoring a hat trick in the first period, he would add one more goal before the end of the game. The Penguins swept the Bruins then swept the Chicago Blackhawks to win their second straight Stanley Cup.
One year later, on May 14, 1993, the Penguins were playing the New York Islanders in game seven of the Patrick Division finals. Early in the first period, Stevens skated in and checked Islanders' defenseman Rich Pilon, hitting Pilon's visor with so much force that he knocked himself unconscious. Stevens landed face first on the ice and, unable to soften the blow upon landing, shattered most of the bones in his face and required extensive reconstructive surgery. Doctors cut an incision below his hairline from ear-to-ear, which was later closed with over 100 stitches, peeled back his skin and reassembled the bones in Stevens' face with the use of metal plates. Stevens came back to have one more strong season for the Penguins, in 1993–94 (41 goals, 47 assists), before being traded the next year.
Stevens was sent to the Boston Bruins in 1995 along with Shawn McEachern for Glen Murray and Bryan Smolinski. Stevens was never given a chance to succeed in Boston except in preseason when he was paired with Adam Oates and Cam Neely. During the regular season Stevens was in Coach Steve Kasper's doghouse and usually played with 3rd or 4th liners. At one point Coach Kasper "benched" Stevens and Neely. Making the two stars sit on the bench for the entire game. The move proved it was time for Stevens to move on but it proved to be the end for Kasper as well. After being traded from the Penguins, Stevens never again reached the success that he had while in Pittsburgh. After "disappointing" in Boston with 23 points in 41 games, he was traded to the Los Angeles Kings. After a poor season, he was traded to the New York Rangers in 1997, where he experienced several solid seasons, but failed to match the expectations levied on him from his marked success playing with Mario Lemieux and the Penguins.
During the 1999–2000 season, Stevens struggled. Not only did he rarely see the ice during this season, but after a game against the St. Louis Blues, he was caught in an East St. Louis, Illinois motel with a prostitute and crack cocaine.[5] After this event, Stevens entered the NHL/NHLPA Substance Abuse and Behavioral Health Program.
After being released from the program, he played a brief stint with the Philadelphia Flyers before being traded to the Pittsburgh Penguins for a second time. After one decent season and another season where he rarely received playing time, he retired from the NHL in 2002.
Stevens returned the Penguins in an off-ice role as a talent scout from 2005 to 2012, including the 2008-09 NHL season, when the Penguins (and Stevens) won their third Stanley Cup. In 2017, he was hired again by the team, this time as a Special Assignment Scout.[6]
Post-NHL
In 2011, Stevens left the Pittsburgh Penguins organization as a pro scout to spend more time with his family. He coached youth hockey including a traveling team in the Boston area.
In June 2015, his son, Luke Stevens, was drafted by the Carolina Hurricanes 5th round, 126th overall pick. Luke played four years of college hockey at Yale University, but was ultimately not offered a contract by the Hurricanes, and signed a minor league contract with the Wilkes-Barre/Scranton Penguins of the AHL in August 2020.
In May 2016, Stevens and a co-defendant were charged with conspiracy and possession with intent to distribute oxycodone.[7]
In May 2017, Stevens entered a guilty plea in a Boston federal court and was sentenced to probation, community service and a $10,000 fine.[8] Stevens admitted to being addicted to prescription drugs since May 1993 (see above) when he sustained massive injuries during a game – an addiction that destroyed his marriage and his post-playing career in hockey.[8]
On January 13, 2018, Stevens' recovery from addiction and his subsequent community service was presented in a 30-minute documentary entitled "Shattered" which aired on Sportsnet, a Canadian sports channel.
Stevens and his sister Kelli Wilson co-founded the Power Forward foundation to combat addiction through education, de-stigmatizing, and recovery programs. It has supported efforts to use therapy dogs in sober homes through a project called D.O.E.R. (Dog Ownership Enhancing Recovery).[9]