Which preposition to use with cheerers

of Occurrences 2%

Second-rate London lodgings are not great cheerers of the human spirit, and Mike was very lonely in his first letter or two; but, as the rehearsals proceeded, it was evident that he was taking hold of his new world, and the letter which told of his first night, and of his own encouraging success in it, was buoyant with the rising tide of the future.

on Occurrences 1%

And so, with tandem on tackle, wedge, or guard back, St. Eustace plowed along toward the Hillton goal, and a deep silence held the field save for the squad of blue-decked cheerers on the seats.

Which preposition to use with  cheerers