Although he is technically still a Lions player, and as such ineligible to feature at The Den on Saturday, the midfielder has effectively drawn a line under his four-year career with the London club.
Tied to the Reebok at least until the end of this season, the 25-year-old pinned his colours to the Whites’ mast ahead of a crucial game at the bottom end of the Championship table.
“I was there for four years so I know the club inside out,” said Trotter, who helped Millwall reach the second tier via the play-offs in 2010. “I’ll be giving as much advice and help as I can.
“It’ll be tough down there, I know that much. Millwall are a team on the up and (manager) Ian Holloway has gone in and done well.
“But that’s the Championship – nothing is easy. Yeovil are bottom of the table and I wouldn’t say that is an easy game.”
Trotter is keeping tight-lipped about whether he has been promised any longer term deal at the Reebok but confirmed that he will not be looking to return to Millwall in the summer.
“My contract is up at the end of the season and I’m looking to move to pastures new,” he said. “We’ll see when that comes.”
Wanderers head to Millwall for the first time since the 2-1 defeat that marked the end of Owen Coyle’s reign in October 2012.
A run of eight games without a win has led to calls from a large number of fans for Freedman to face the same fate.
The Wanderers boss has questioned the mental resolve of some of his players in the last few days, and with that in mind, there can be few less appealing venues to be travelling to than The Den to try and change his fortunes.
But Trotter insists the renowned hostile atmosphere at the ground can also work against the home team.
“It’s a difficult place for away sides, a good atmosphere, and everyone knows the fans are very, very passionate and try to get behind the team,” he said.
“But at times you can turn them against the team. That’s what Bolton have got to try and go down there and do.
“We need to impose our game on them and hopefully that means our quality ca shine through and get a result.”
Trotter remains convinced that Wanderers will soon turn a corner under Freedman and that he has not swapped one relegation battle for another.
“One win can spark a run, that’s how we have got to look at it,” he said.
“But first thing’s first, we’re only five points clear of the relegation zone.
“I came from a club only two points away in Millwall, so I know all about the situation I have stepped into.
“I also saw the potential here and I think there is potential to do great things.”