McAllister, 23 has ended his loan spell after the Irish midfielder dismissed at home to Aldershot last Saturday and after losing his appeal a three match ban will take him over his loan spell.
He has played fifteen matches at the Greenhous Meadow club since making his debut in a 2-0 win over Gillingham in mid-January. "It's really disappointing. I've loved my time at Shrewsbury and I felt I was getting better and better every game," he told BBC Shropshire. It's been a very positive move to play here. I only came over to England last year from Ireland and to really get a nice run of first-team games has helped me. They're (Shrewsbury) definitely up there with the top teams in the division and I think they'll go up, as I think Sheffield United will, to the Championship."
He will miss Sheffield United's fixtures against AFC Bournemouth, Rochdale (at Spotland) and Leyton Orient and will be made available for selection at Milton Keynes Dons on 21 April.