RYAN Leonard will be out for "a number of weeks" after inuring his knee against Leeds United before the international break.
Leonard went off in the 28th minute and was replaced by Shaun Williams.
The former Sheffield United midfielder will miss this weekend's trip to Brentford.
Jiri Skalak could be available for the Griffin Park clash.
Caretaker Adam Barrett told Millwall's website: “Unfortunately, Ryan Leonard will be on the sidelines for a number of weeks, which is really disappointing because he has come into some good form lately. He was excellent until he had to come off last weekend.
“Jiri Skalak, we’ll wait and see with. He’s been back in training which is great, so we’ll continue to monitor him. Other than those two lads, we’re good to go.”
Meanwhile, Gary Rowett and Gareth Ainsworth are the bookies favourites for the Lions job. A report on Monday claimed Millwall had approached Wycombe for Ainsworth.
Barrett is set to be in charge against the Bees.
He added: “Our sole aim is to go to Brentford and make sure we can go and get a result. Everyone is in a good place, we continue to wish all the lads well who are on international duty, and hopefully they come back with no problems. From there, we’ll get the preparation sorted for next weekend, which we look forward to.”
“It’s been well-documented how much of a whirlwind it’s been for myself and around the club, of course, but I’m really enjoying it. It’s been excellent so far, and hopefully that can carry on.
“It felt right [against Leeds], and I enjoyed stepping up to the plate and leading the chaps. We’re now moving straight onto Brentford, that’s the main focus.”
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