The Lions have also captured 25-year-old former Wycombe utility player Danny Senda, who almost joined Luton earlier in the summer.

Trotter has just turned 18 and moves to the New Den immediately after signing a two-year professional contract with the Championship club.

"Playing regular football is the next step for me and I am really looking forward to it," said Trotter.

"We're delighted to have offered Liam his first professional contract," said Town boss Jim Magilton. "Now he needs to get some first-team experience."

Meanwhile, Senda spoke of his delight at signing for the Lions.

"Having received an offer from Millwall at the 11th hour I have jumped at the chance because this is a big club with ambitions to go places," said Senda.

"If I'm involved on Saturday I'll be hoping to show the fans what I can do."