The Bucks’ National League North play-off place is a little more precarious after their 3-1 loss at Brackley Town on Saturday.
And 31-year-old Streete – the second-oldest player in the squad behind Matthew Barnes-Homer, 33 – did not start after recently battling through a minor injury.
He has had knee problems in the past too, but Cowan says they are not having to watch him closely due to that – but because of his age.
“It’s not so much his injuries because he’s over those injuries now,” said Cowan.
“He’s had an injury over the last few weeks, which is just a standard injury which he’s over now.
“But he’s getting to that sort of age now, isn’t he?
“It was a little bit later for me, but when you approach your mid-30s you have to manage your body. It’s common-sense.”
Telford conceded all the goals at St James’ Park in the first half, when Streete was not on. He came on for the second period and on if his presence was missed in the first, Cowan said: “Yes. But you always (miss it).”
“We’ve got another 14 games to think about in the league.
“Of course you miss his presence, but I’ve got other big players on the pitch.”
Meanwhile, Cowan has stressed the Bucks, who host Guiseley tomorrow, are still aiming for a top-half finish first and foremost.
“Where we’re at now, we want to maintain that top half,” he added. “If we can start gaining points, it’ll be the play-offs.”