The 39-year old was blasted in his leg as he walked across the forecourt of the Jet petrol station, Woodhouse Mill, yesterday morning.
Detectives investigating the incident said it was a 'targeted attack' and the culprit is still at large.
The victim was rushed to hospital, where he remains today. His injuries are not believed to be life threatening.
South Yorkshire Police said the victim was shot by the passenger of a black Seat Leon which pulled up alongside him at 9.10am yesterday.
The attacker and their driver sped off, leaving the injured man on the forecourt.
Descriptions of the attacker and accomplice have not yet been released.
Detectives said they are not linking the shooting to any other incidents.
Detective Inspector Mark Monteiro said: “We understand that incidents like this cause concern amongst the local community, but I’d like to reassure you that we take all such incidents extremely seriously.
"We are treating this as a targeted attack and are continuing to work with the victim to establish the exact circumstances around what happened.
"At this time, the motive to the incident is unknown. We’d like to continue to ask anyone who saw what happened to call and speak to us."
Call South Yorkshire Police on 101 or Crimestopper on 0800 555111.