Ryan East says the younger Royals in the squad will need to get used to the ruthlessness of senior football, after a 1-0 friendly defeat to Lincoln City on Saturday morning.
After a generally youthful side went up against the Imps and competed for the majority of the match, a late winner from Harry Anderson gave the League One side victory in Marbella.
While the result on the day was secondary to the performance, young midfielder East said there was still plenty to be taken from the game.
"I thought we competed really well. But I think it shows that, at senior level, one mistake can cost you the game. All round, we did well.
"They won League Two last year so we knew we weren't competing against any old team - it was a tough test.
"Apart from Sam [Walker and Baldock], the whole team have played Under-23s football and come through the Academy.
"I think it shows how far we've come to be able to compete with a League One team. Hopefully we can keep doing that and keep pushing on.
"Some of us have played one, two, three senior games, so it's all about pushing on and getting more appearances for the first team - which is what we all want to do. This is the club we've been at for a long time, so this is what we're trying to do.
"We're all here, trying to show the manager what we can do and hopefully we can push on this season.
"The tour has gone really well. For all of us young lads, it's good for us to get in amongst it, get experience with the senior players and they'll get to know us.
"As a whole, I think it's been really good for the team. Apart from today where we've lost, the games have been really beneficial for all of us.
"Pre-season hasn't been too long but it's been really tough, we've all worked really hard. When we get to that first game of the season, I'm sure we'll be ready."