Ertl, 29 missed the first quarter of the season through injury and since his return has seen first time action limited - his last appearance coming against Salisbury City in the FA Cup on 7 January.
He is out of contract in the summer but despite his possible departure he insists that he wants to remain at Bramall Lane next season; "It was quite quiet during the window to be honest, which suits me because all I am focused on is doing my best for Sheffield Unitedand trying to break back into the side," he told Sky Sports. "I'm not really interested in going anywhere else in the next few months and there was a bit of interest, but I want to stay here and help this club achieve promotion like everybody else here."
Last month it was thought that he would leave United and join 2. Bundesliga (second tier) side TSV 1860 Munich but no move materialised.