In his three seasons with the Filbert Street club, Trueman made 47 first-team appearances, scoring three goals, before a move in May 1908 to the south coast to join Southampton of the Southern League.
Despite being considered too small to be a half-back, Trueman soon proved that his judgement and skill made up for his lack of height and he showed himself to be "quick, resourceful and decisive in action (who was) overall a most difficult obstacle for opposing forwards".
He soon became established at left-half, alongside Frank Thorpe or Sam Jepp in the centre and John Johnston on the right, although Trueman was able to play in any of the half-back positions.
[1] Soon afterwards, Trueman grew restless at The Dell and in March 1911 was allowed to return to the Football League with Sheffield United.
In September 1916, Trueman was visiting Filbert Street when he was persuaded to turn out for Leicester in a war-time game against Grimsby Town as the home team were short of players.