Valve rocker supports

Can anyone tell me the purpose of the supports for lack of a better term that are installed on the 4.9 liter engine on the rocker arms? They seem to be a support for the rockers so they don't slip off the pushrods but I am not sure. We broke two of them putting them back on after replacing an intake manifold gasket and were wondering if they are really important or? Thanks in advance.

Pictures would work wonders.