Seamus Casey will miss the first few months of the 2026-27 NHL season after undergoing knee surgery with an expected recovery timeline of eight to 10 weeks, [prohockeyrumors.com] reported. The 22-year-old New Jersey Devils defenseman sustained the injury during a September 24 preseason contest against the New York Rangers, according to club announcements.
Knee Surgery Postpones Season Debut for Seamus Casey
The latest procedure sidelines Casey until late November or early December, forcing the offensive-minded right-handed defenseman into another lengthy recovery early in his professional career. [prohockeyrumors.com] noted that Casey's current issue stems directly from the early-season matchup against New York, an incident that initially prompted head coach Sheldon Keefe to state the player would miss some time before surgical intervention became necessary. [nhl.com] added that Keefe confirmed the player's post-surgery status, stating that the recovery window sits firmly at eight to 10 weeks.
“He’s doing well in the sense that he got through surgery well,” Keefe said, as [nhl.com] reported. “It was from the injury sustained in that Rangers game. It’s about an 8-10 week recovery is what they’re saying at this point.”
Ongoing Health Struggles Threaten Early Professional Development
The timeline represents another significant setback for a prospect who has played very little professional hockey over the past calendar year. [prohockeyrumors.com] outlined that the University of Michigan alumnus began the 2025-26 campaign late due to a lingering lower-body issue from training camp before a separate knee injury ended his season in February. By the time Casey returns from this latest operation, he will have missed nearly a full year of competitive games at either the NHL or AHL level since January.
“Difficult for him. Of course, he’s fought some injuries and tough start to the season,” Keefe said, according to [nhl.com]. “In terms of how everything went, he’s doing well. He’ll start his rehab and we’ll get him back on the ice as soon as we can.”
Roster Impact on the New Jersey Defensive Corps
When healthy, Casey has demonstrated clear offensive upside at the professional level. During his 2024-25 campaign, [prohockeyrumors.com] documented that he scored four goals and eight points in 14 games with New Jersey while averaging 12:39 of ice time, followed by three goals and 18 points across 30 games with the AHL’s Utica Comets. In the 2025-26 season, prior to his shutdown, he added one goal and 19 points in 21 games for Utica alongside a -13 rating, though he appeared in only one NHL contest.
The extended absence leaves New Jersey relying on existing right-handed depth. [prohockeyrumors.com] reported that while the Devils possess Dougie Hamilton—who has two years remaining on his contract—alongside Brett Pesce and Johnathan Kovacevic, none match Casey’s specific offensive ceiling. Meanwhile, [nhl.com] noted that Kovacevic recently returned to full team practice after missing training camp and the preseason with his own knee injury, beginning the process of building up his workload for game situations.