Colchester United have signed experienced striker Chris Porter and versatile defender Matthew Briggs.

Porter, 31, has signed an 18-month contract after having his contract cancelled by League One rivals Sheffield United. He spent three-and-a-half years with the Blades, scoring 23 times in 118 games, but has not played since November.

The ex-Bury, Oldham, Motherwell and Derby front man scored four times as Nigel Clough’s side reached the FA Cup semi-final last term.

Briggs joins on loan from Championship strugglers Millwall until the end of the season. The 23-year-old, primarily a left-back, became the Premier League’s youngest-ever player in 2007 when he made his Fulham debut aged 16 years and 65 days.

The former England Under-20 international never fully established himself in the Cottagers’ first team squad though and, after brief loan spells with Leyton Orient, Peterborough, Bristol City and Watford, he signed for Millwall on a free transfer last summer.

He has made 11 starts and one substitute appearances for Ian Holloway’s side this season.

The U’s – joint-bottom of the table – sold leading scorer Freddie Sears to Ipswich Town last week for a fee believed to be around £100,000, signing young striker Jack Marriott (20) on loan from their Suffolk neighbours.

Cardiff City loanee Rhys Healey (20) led the line in last Saturday’s 2-0 home defeat against Walsall, while Alex Wynter started at left-back. Tony Humes’ other forward options include youngsters Gavin Massey (22), Macauley Bonne (19) and Dion Sembie-Ferris (18).

The Essex side host regional rivals and fellow strugglers Leyton Orient on Saturday.