Neil Harris hasn't ruled out adding one more player to his squad before the transfer window shuts on Thursday night.
The Lions boss says he's open to an eighth summer signing but won't risk losing a "tightness in the squad" by having too many players.
"It's about striking a balance," Harris told millwallfc.co.uk
"We are looking at who is available and we may bring in one more to give us that extra depth - but these things are delicate.
"You don't want players to be left out of the squad because there are too many players, that can cause unhappiness within the group.
"You want to have a tight-knit group and that's what we have right now. The squad is fit and everyone is competiting for places - that's the way I like it.
"However, if I feel we could use another player then I will add it. He will have to be the right character and influence and someone with the ability to come in and add to what we have already got."