Cotterill fought back from severe ill health to take in his first game in more than four months, following more than 60 days in hospital, as Shrews were edged 3-2 in a rollercoaster clash against the play-off chasing U's.
The manager delivered an emotional meeting to his players and staff in the home changing room before the game, some four months exactly since he last faced them. The experienced boss, who spent a weekend in intensive care and battled pneumonia, shared how close the virus came to taking his life, and told his players to appreciate everything they have.
Cotterill, 56, spent the entirety of the thrilling contest in the directors' box at the back of the Roland Wycherley Stand. He became more vocal as the clash went on, and spent most of the second half bellowing down instructions to the sidelines and pitch.
"We found out on Thursday he was coming back and he gave a little speech before the game," said Shrewsbury midfielder Josh Vela, who scored his side's second goal, which handed them a 2-1 lead at the interval.
"It was quite emotional, about what he's been through and stuff like that. It really gave us a little lift to go and win the game for him.
"We couldn't do that but he was pleased with our efforts and how we played the game.
"It was brilliant. He was still the same, coming in shouting and making everyone laugh.
"His speech was emotional, we know what he's gone through, it's been a difficult time. But now he's back and he looks and feels a lot better.
"It's unbelievable what he's been through, like what he was saying, he was close to dying, that's what it was all about and how emotional it was before the game.
"But the type of person he is, the character he is, he's come through that and everyone's just pleased to see him back for the boost for next season."
The U's pounced on an early error to lead through Elliot Lee but Matthew Pennington headed in an equaliser soon after, before Vela's well-taken finish.
But James Henry converted midway through the second half before visiting substitute Dan Agyei struck a deflected winner five minutes from time.
Cotterill is set to remain in place for the two remaining fixtures of the season, at home to Ipswich tonight and Sunday's curtain-closer at Crewe.
Town remain 17th with six points left to play for. They can only finish as high as 16th come next weekend.
Vela said of the manager's return: "One hundred per cent, football comes second when someone you look up to has had health problems like he has.
"But he's come through it as a fighter and seeing him back today was unbelievable.
"He's got a family at home, he's got children. But he came in just virtually the same as when he last left us four months ago.
"He was the same person, still shouting at us, making us laugh, he's a massive character in the game and we're happy to have him back."
The midfielder added: "He came in to keep us up but, with the four months away he's had, if he'd have been here I think we'd have had that extra chance of moving up the table.
"But obviously Albie and Davey Longwell have done brilliant to keep us going and getting us over the line, but I reckon if he was here we could've really pushed up the table.
"He was the same as he was before, cracking jokes, calling us – well I can't say on here what he was calling us! But that's what he's like, it's like he's never been away."