As the clock ticked down to zero in the Beanpot consolation game, there was frustration on the faces of the team begrudgingly exiting the home bench at the TD Garden.

Boston College players and coaches were faced with the program’s first fourth place finish since 1993, and more startling, a third consecutive loss for a team that is on the bubble of the magic line in the Pairwise Rankings.

Jerry York’s team remains in first place in Hockey East, but four stiff tests remain including this weekend’s home series against Vermont and a home-and-home series with UMass Lowell to conclude the regular season.

Despite being in first place, there have been lows that Eagles fans are unaccustomed to experiencing. BC lost to Merrimack at Conte Forum on Friday night, the first such defeat on home ice since Halloween night in 1997. The Eagles went 0-3 against archrival BU, being outscored 8-2 in those three contests.

When your top two centers are Colin White and Austin Cangelosi, it’s a good bet your team will be at the top of the standings. Despite his rocky start against Merrimack, freshman Joe Woll has been very good overall.

The reason the Eagles find themselves in a downward spiral is simple. Seven players left early for the NHL after last season. Thatcher Demko was a Hobey Baker Finalist and a very good collegiate goaltender. Alex Tuch, Zach Sanford, Miles Wood and Adam Gilmour provided offensive firepower.

However, none of those departures are the culprit for why the Eagles find themselves precariously on the NCAA Tournament bubble. The losses of star defensemen Steve Santini and Ian McCoshen were the cogs on the blue line that have not been replaced.

Connor Moore, Luke McInnis, Jesper Matilla and Michael Campoli were brought in on the blue line. The four had varying degrees of pedigree and international experience prior to arriving at The Heights.

McInnis is known for his offensive capabilities, but has struggled defensively in a major way this season. Moore has been the best of the four in his own zone, but he too has had his ups and downs as a rookie in Hockey East. Matilla has battled injury and has looked just mediocre going backwards. Campoli, a NTDP alum, has regressed and never reached the potential some saw in him back during the recruiting process.

Michael Kim, a former NESCAC recruit, has developed as a sophomore and turned into the most reliable of the six defensemen Jerry York trots out on a nightly basis. A good skater, he can break the puck out of his own zone and move the puck effectively.

Classmate Casey Fitzgerald retrieves pucks well, grinds hard and is also a good skater, but he’s been prone to making mistakes and being caught out of position, forcing him to take costly penalties.

Senior Scott Savage has been solid at times and can provide a bit of a physical presence and veteran leadership out there.

Reviewing tape of the Merrimack loss, one doesn’t have to look too hard to find defensive lapses. There were defensemen caught pinching and bad gaps in transition. Defensemen were caught on the wrong side of the puck which allowed Merrimack players unimpeded access to the net front. There was a lack of engagement. Simple net front coverages were blown. There was a lack of urgency that gave the Warriors a chance to transition quickly and establish offensive zone time.

Greg Brown is one of the best defensive coaches in the game and Mike Ayers is a respected assistant coach as well, but some things just can’t be taught. The personnel in place just can’t defend well enough on a consistent basis to succeed at the Hockey East level. It will be the reason the Eagles exit the Hockey East Tournament early and why there will likely be no NCAA Tournament for York’s bunch for the first time since 2009.

While goals have been hard to come by at times, the offense is not the problem. The goaltending can’t be blamed for the shortcomings either. When it comes down to it, the biggest issue facing the Eagles is a lack of reliable defenders who can be counted on to make plays and keep the puck from going in the net.