They also serve who only stand and wait. As the Reading manager, Steve Coppell, emphasised the importance of his squad's mentality, and specifically the patience of certain members of it, his substitutes helped themselves to three of the goals as Reading wrapped up the Championship title with what was - eventually - a champagne performance befitting the occasion.
"People have asked me what the secret has been this season," said Coppell, "and in many ways it is those players who have come on and injected that bit of something, those who have been supportive without being disruptive.
"It's easy to be me-oriented in football," Coppell added, "and for those players to be selfless and give when they're not in the limelight has been a significant part of our success."
After an first half of what Coppell termed "testimonial football" in which the only incident of note was the roar greeting Stoke's goal against Sheffield United - whom Reading needed to drop points if they were to seal the title - goals from James Harper and Dave Kitson had Reading in control when the substitutes arrived. John Oster sidefooted the third within a minute of his introduction, and while Shane Long took twice as long to make his mark, he made up for his relative tardiness by rattling in a fifth as well.
"It's brilliant," Long said. "I came here with Kevin [Doyle] from Cork City and not that much was expected. I was just looking to keep my head down, but for this... I remember [Coppell's assistant] Wally Downes telling me to get across the front post; I make those runs every day, and this time they came off."
His main concern, though, was for his mother, with whom he shares a flat in Reading. "She missed the Leicester game [when promotion was secured]," he said, "but she was here for this with here sister, so it's a nice day for them."
Long's contribution was the most eye-catching, but just as much in Coppell's thoughts was Chris Makin, the full-back who was a regular until being injured against Stoke in October. He was replaced by Graeme Murty and "without doing much wrong", in Coppell's words, has been unable to win his place back. On Saturday, he was not even on the bench.
Inevitably, even with five games remaining, thoughts are turning to next season, and the task of staying in the Premiership. Already Reading's chairman, John Madejski, is warning that there will not be a vast transfer kitty.
"We've done some pilot schemes in terms of ghost budgets," Madejski said. "But we've a £10m overdraft so we're not flowing with milk and honey. I don't envisage too much strengthening."
Long spoke optimistically of the squad being "good enough already", but Sunderland's struggles this season have proved that team spirit alone is far from being enough in the Premiership. That, though, is for the future; for now Reading's concern is not of Premiership lows but of a happier Sunderland record - the 105 points they got in winning the division in 1999.
Goals: Harper (59) 1-0; Doyle (65) 2-0; Oster (70) 3-0; Long (74) 4-0; Long (83) 5-0.
Reading (4-4-2): Hahnemann; Murty, Sonko, Ingimarsson, Shorey; Little (Oster 69), Harper, Sidwell, Convey (Hunt, 68); Kitson, Doyle (Long, 72). Substitutes not used: Stack (gk), Gunnarsson.
Derby County (4-1-4-1): Camp; Jackson, Moore, Nyatanga, Wright; Idiakez; Smith, Barnes, Bolder (Bisgaard, 72), McIndoe; Peschisolido (Ainsworth, 72). Substitutes not used: Poole (gk), Thirlwell, Hanson. Referee: A Bates (Staffordshire).
Man of the match: Sidwell.
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