Missing fuel injector cap

[G-531848]

While replacing the intake manifold gasket I found an injector noosing it’s cap. The cap was not in the combustion chamber but I can’t find it. Can I run the car without it

 

[melsg5]

this is an injector for the 2005 4 cylinder engine, so what part do you consider a cap?

https://www.napaonline.com/en/p/CRB238881?impressionRank=3