Town defender James Krause's loan at Carlisle has been extended until the end of the season. The 20-year-old left-back or centre-half has been with the Cumbrians for the last two months.
Manager Neil McDonald said: "He has impressed us a lot, and part of the thinking behind allowing Simon Grand to leave was the fact that we wanted to keep James here.
"He has done well since he arrived, and we're looking forward to working with him throughout the remainder of the season."
Krause, whose current loan was due to expire on January 20th, has made two starts since moving to Brunton Park.
Meanwhile, Town are reported to be amongst a number of Championship clubs keeping an eye on Bradford City's Jamaican midfielder Jermaine Johnson.
Johnson, whose previous English include Bolton, Oldham and Yeovil, spent time on trial with the Blues in January 2001 when he was first looking for a club in the UK.
Stoke and Hull are also reported to be interested in the 26-year-old, who signed a one-year deal with the Bantams after joining them from Jamaican side Tivoli Gardens in the summer.