I am in the process of doing a CL-S swap and was doing a valve job before putting the engine in and noticed that one of the exhaust rocker arms is missing its bearing. This bearing is the one that rolls against the camshaft to actuate the valve

I have no idea what could have happened to the bearing, unless it simply never came with one from the factory but the engine has 65,000 miles on it.

Here's what it looks like below.


Any ideas? I'm going to do a compression test and drop the oil pan to make sure there isn't bearing fragments in there after putting in a new rocker and camshaft.