The woman was pushed to the ground and punched by a cyclist on January 16, West Mercia Police said.
The incident happened at about 11.30am at The Lloyds.
The suspect is described as white, about 60 years old with grey hair and a grey beard.
Investigating officers have now released a picture of a man they believe could "help with inquiries".
Anyone with information can contact West Mercia Police on 101, quoting incident reference number 00196_I of January 16, 2021.
Alternatively, contact Crimestoppers anonymously on 0800555111 or crimestoppers-uk.org