Manchester United announced they had signed Bayern Munich midfielder Marcel Sabitzer on loan in the early hours of Wednesday.
United were forced into deadline-day action on Tuesday following an ankle injury to Christian Eriksen, which is set to rule the Denmark midfielder out until early May.
Manager Erik ten Hag completed the loan signing of Netherlands forward Wout Weghorst earlier in the January transfer window.
Sabitzer, 28, who was previously club captain of RB Leipzig, has won 68 caps for Austria.
He played 24 times for Bayern this season.