The Spireites weren’t as sharp in the 1-1 draw at Boston United as they have been before in pre-season.
But Allen was happy with what he saw - and told the club’s official website that things will come together.
"It was a slow start and we didn't really get going into top speed,” he said. “However, when you reflect on it, that's the first game for a lot of players - for some it will be their first match in a couple of months.
"We've trained very hard this week, especially on Thursday, with the aim of getting everyone fit for a few weeks' time. I think that probably took some energy out of those younger players and perhaps some of our older ones, too."
Chesterfield begin the season with a trip to Ebbsfleet United on August 4.
"We changed it around and freshened up a little bit, and those lads that came on dominated the game, but we never made a chance," Allen told the website.
"I don't think we were anywhere near as sharp as we were against Sheffield FC, but overall I know that behind the scenes we're fitter. The good points today are that I've managed to see all our players - some of them boys have done really well and I'm pleased with them.
"Just about everybody's played about 90 minutes now and by the end of next Saturday every player will have played at least 90 minutes and have had a good run around to improve their fitness levels, which is what it's really about."