At around 7.20pm, a man approached the victim, a man in his 50s, on Arthur Road and threatened him before stealing his wallet.
The man was not hurt.
Police would like to speak to anyone who was in the area at the time and may have seen or heard anything.
Police are particularly keen to speak to the man pictured, who was seen in the area at the time and may have information that can assist our enquiries.
If you recognise him or have any information, call 101 quoting 44210156220.
Alternatively you can contact independent charity Crimestoppers anonymously on 0800 555 111.