Last updated on .From the section Football

Andy Kellett (right) came through Bolton's academy but only made his senior debut last April

Manchester United have signed Bolton defender Andy Kellett on loan until the end of the season, with Saidy Janko moving the other way.

Kellett, 21, has only made four senior appearances for Bolton and spent three months on loan at League Two Plymouth Argyle earlier this season.

Midfielder Janko, 19, has yet to make a senior appearance for United.

Last week, defender Sadiq El Fitouri, 20, joined the Premier League side from Evo-Stik First Division Salford City.

Who is Andy Kellett? Made his first senior start for hometown club Bolton in the 4-2 league defeat by Rotherham in January His only senior goal to date came while on loan at Plymouth Argyle, during a 3-2 win at Northampton on 13 December Kellett became the first Bolton-born player to play for the Trotters in eight years when he made his senior debut against Leicester on 22 April, 2014 Former Bolton boss Dougie Freedman said he had reservations about Kellett's ability to break into the first-team reckoning

Kellett came through Bolton's academy and only made his senior debut for Wanderers last year.

He joined Plymouth in October, scoring one goal in 15 appearances for the Devon club.

Kellett is United's third signing of the January transfer window, following moves for El Fitouri and former Barcelona goalkeeper Victor Valdes.

Analysis from BBC Sport's Simon Stone:

"A series of loans have reduced the options available to Manchester United Under-21 boss Warren Joyce. So when the decision was made to let 19-year-old Swiss youngster Saidy Janko compete for a first-team place at Bolton for the remainder of the season, Joyce needed his squad replenishing. Kellett has been offered the chance of a lifetime, one he could not have thought possible a week ago."