Town were scheduled to play four warm-up fixtures this summer – all on the road – before a clash at Tamworth two Saturdays ago fell by the wayside for medical reasons.
Instead Shrews have enjoyed run outs at AFC Telford United and Hereford so far, chalking up two wins, and round-off their friendly programme with a behind-closed-doors contest at League Two Exeter this Saturday.
Cotterill admitted he would have preferred four friendlies, but due to Shrewsbury's light squad currently featuring around 16 senior pros, the minutes built up over the three matches will more than suffice. The boss revealed Town supplemented losing the Tamworth clash by upping the ante further in training.
He said: "It's because of a smaller squad. If we had five friendlies, you probably wouldn't ask me that.
"In the first two, what normally happens is everybody plays 45 minutes - it's about how many minutes they get really.
"When you look at the size of our squad, our lads have already got now 180 minutes behind them.
"Then it'll be another 90 minutes on top (at Exeter) and all of a sudden the minutes add up.
"Whereas if you've got a massive squad and play five games, they sometimes end up playing less minutes."
Cotterill added: "It's not ideal, playing three friendlies, would I have liked four? Yes I would've. But it was down to unforeseen circumstances and we're accepting of that.
"We move on but we train a little bit harder. Three is not quite enough but it's three good ones and we'll supplement it with training in between."
Cotterill, who took in Bristol City's friendly win over MK Dons on Saturday, also insisted that pre-season results are unimportant, with the focus on fitness.
"All in all, when I think about what we've done, I'm really, really pleased. I don't have any fears of us playing three games as opposed to four or five games, the minutes they get in will definitely be equal to what we'd have if it were a bigger squad," the boss said.
Meanwhile, Shrewsbury international duo Aaron Pierre and Ollie Norburn are set to meet up with their club colleagues today after representing Grenada in the Gold Cup in the USA.