WASHINGTON -- Tom Soehn's decision not to seek an extension to his head coaching tenure at D.C. United caps a difficult year for the team and adds another question to the capital club's lengthy offseason agenda.The squad continues daily workouts and fitness sessions under assistant coaches Chad Ashton, Mark Simpson and the rest of the United training staff this month. But the departure of their long-serving boss has hammered home the hard reality of their shortcomings over the past two years -- and the resulting consequences."I know how D.C. United is and it's not acceptable to not have great seasons and make the playoffs, so I know there'd be changes but I didn't know where the changes would take place," said midfielder Clyde Simms on Wednesday morning. "In that head position, [Soehn] has to take a lot of the blame, but as players we're a big part of that also. It's disappointing for us also."After years of injuries and a harrowing battle with drug addiction, Santino Quaranta has revived his career under Soehn's guidance and on Wednesday the 25-year-old paid tribute to his former coach's role on his road to recovery."Tommy, he helped me a lot. He was the one who helped me come back -- he was the first person I asked," said Quaranta. "He made me feel comfortable, he made me feel like I was a part of it again."Quaranta also attributed his U.S. national team call-up this past summer to Soehn's advocacy on his behalf, and readily acknowledged that the coach paid the price for his team's underachievement."It's not a happy time. We knew it was shaky ground from the start, from when we didn't make the playoffs. It was uncertain," he said of Soehn's job security. "A lot of times it was our fault, you know? We didn't really help his cause out a lot in the end."The close of Soehn's three-year reign has also brought down the curtain on one of the most frenetic and pressure-packed chapters in the club's history, a period of profound ambition as well as crushing disappointment. Since returning to glory with their 2004 MLS Cup championship, United have aggressively pursued both domestic and international honors only to fall short under the weight of unprecedented physical and schedule demands and, ultimately, high expectations themselves.In three seasons, Soehn led D.C. to a winning record through 134 competitive matches overall, which averages out to nearly 45 games a year -- about 50 percent more than the average MLS regular season -- and those taxing schedules inevitably took their toll on players and coaches alike.United were keen to carve out success in the CONCACAF Champions Cup and its successor, the CONCACAF Champions League, but struggled to do so given the timing of the tournaments and the demands they placed on budget-conscious MLS rosters."It's hard to sustain so many games and keep your rhythm and flow. ... It's almost like the successful teams now carry a lot more burden than the other teams. So is it being punished for doing better, or is it being rewarded?" said Soehn last week."Every time we had a stretch where you could work and prepare for a team, it became a lot easier. But it's not just the physical grind, it's the mental preparation too. Figuring out your opponent, how to play against them and working on things. So that's been a real strain and I'm still not sure what the right answer to that is, because it's difficult with our roster scenario."A hard-nosed defender with Dallas and Chicago during the early years of MLS, Soehn spent three years as an assistant to former D.C. coach Peter Nowak before ascending to the top spot in 2007. He led United to a second consecutive Supporters' Shield in that campaign and captured the U.S. Open Cup title last year, but found himself under growing pressure as CONCACAF and MLS Cup glory continued to elude the Black-and-Red, and his position became nearly untenable last week after D.C. missed out on the playoffs for the second consecutive season.Club executives Will Chang, Kevin Payne and Dave Kasper were still considering whether to offer Soehn a new contract, but on Monday he informed them of his decision not to return, having mulled the future with his wife Jean and their four children."Any time you go through difficult stretches, you rely on your family a lot to make sure you come up with the right decisions. And it wasn't an easy decision," Soehn told Comcast Sportsnet on Tuesday. "Coming to D.C. was something that was dear to my heart and working here for six years, you become part of the organization and you really have a love for it. Sitting together, we just felt -- and this was a decision we came to together -- that it was time for a change and time to move on. ... You kind of know in your gut when it's time."