Howard was appointed captain while at Barnsley
Millwall have signed Reading's Brian Howard on a three-month emergency loan.
The 28-year-old midfielder has made 70 appearances for the Berkshire club in all competitions since signing from Sheffield United in 2009.
Royals boss Brian McDermott said: "He feels he's at a stage where he wants to be playing regular first team football and we couldn't guarantee that."
The ex-Swindon man could feature for the Lions in their Championship clash against Watford on Tuesday.
McDermott added: "I have got nothing but positive things to say about him. He goes to Millwall with our very best wishes."
Howard, who began his career at Southampton and enjoyed an impressive spell with Barnsley, will be out of contract at Reading in the summer of 2012.