"As and when I can bring in new players I mast make sure they are players that can bring something to the team," he says, after fielding a side against Atvidabergs on Tuesday that included, at the end of the evening, four players - Daryl McMahon, David Noble, Trent McLenahan, and Youssef Sofiane - that have never played in a competitive match for the first team before.
"You don't want to get into that situation; it is the last thing you want to do especially as West Ham have some very high standards to maintain - and we will do whatever we can to maintain them through this season that will give us the best chance to be promoted," he adds.
Jermain Defoe and Joe Cole grabbed a brace each and Glenn adds:
"Jermain and Joe, like the others, have been superb since they have come back into preseason and have put a great deal of effort into their training every day.
"The physical training has been greatly increased but you are a little bit uncomfortable with so few players in case you break them down.
"But what do you do? If you don't train them hard they are not fit enough, so we are taking the gamble that we will work them extremely hard top make sure they are in the right physical condition for the opening game of the season.
"We are working hard with the ball as well, getting in double practices, not so much this week because there is, after tonight's game, a recovery period which will be Wednesday, and we will train Thursday morning before we go into a very good preseason game against Djurgardens.
"I haven't seen anything in any of the players that suggests that I should be concerned about their attitude and Joe has scored three goals in two preseason games, Jermain has chipped in with a couple - as has Hutch - and it was very pleasing tonight.
"I don't like to concede goals but on the flip side it was good to score five, which is difficult at any time.
"But it is only two games, there is a lot of work to be done in the next two and a half weeks, and we are looking forward now to our next game which will be our toughest so far."