Daniel Gittins, aged 28, tried to steal money from a man in Telford on August 12 last year.
Several weeks later, on September 30 last year, he attacked another man in Telford.
Gittins, of Beaumont Court, Church Stretton, pleaded guilty at Shrewsbury Crown Court to attempted robbery and inflicting grievous bodily harm.
Olivia Appleby, representing Gittins, asked for the case to be adjourned for pre-sentence reports so probation service workers can explore and discuss his pattern of offending.
Recorder Jason MacAdam agreed and put Gittins' sentence back to September 15.
He told Gittins: "I have no idea what sentence is going to follow. All options are open."
Gittins was remanded in custody until his next court date.