Ferguson was a stalwart of Liverpool's defence shortly before the First World War. He made his debut on the opening day of the 1912-13 season and was the club's only ever-present that year and only missed two league games the following season. The 1914-15 season was completed despite the outbreak of war but Ferguson lost his place in the side to Donald MacKinlay after a third of the season and only briefly threatened to claim it back on a regular basis.
The Liverpool Echo commented on Liverpool's capture of Ferguson at the time: "Liverpool made a good stroke when they signed Bob Ferguson. The Third Lanark supporters are deeply sorry to lose their favoured centre half, who is described in Scotland in the following eulogy: "There has never been a more likable player. Honest Bob would be the correct title for him for he was always playing the game to the delight of his friends. He was the sort of man a club manager likes to have under him - dependable, keen for his club's interests and never likely to get himself or the team into disrepute. Mr. Watson has made a catch and he knows it."