Birmingham have completed the double loan signings of Manchester United defenders Tom Thorpe and Tyler Blackett until the end of the season.
Highly-regarded centre-back Thorpe is captain of United's under-21 development side and represents England at under-20 level.
Blackett, 19, predominantly operates at left-back but can also play at centre-half or on the wing and also boasts international experience with England.
The pair, who can both be recalled by United after 28 days, are available to make their Blues debuts in Saturday's Championship clash at home to Derby.
Boss Lee Clark has moved to bolster his defensive ranks after Kyle Bartley and Dan Burn were recalled by parent clubs Swansea and Fulham respectively.