Separating 'cargo package' from 'cargo publish'

When I run cargo publish, I see:

    Updating crates.io index
   Packaging lammps-sys v0.5.0 (/home/lampam/cpp/other/rust/lammps-sys)                                                                                      
   Verifying lammps-sys v0.5.0 (/home/lampam/cpp/other/rust/lammps-sys)
    Updating crates.io index
   Compiling version_check v0.1.5                                                                                                                            
   Compiling cfg-if v0.1.6
   ...                                                                                                                                    
   Compiling env_logger v0.4.3                                                                                                                               
   Compiling lammps-sys v0.5.0 (/home/lampam/cpp/other/rust/lammps-sys/target/package/lammps-sys-0.5.0)                                                      
    Finished dev [unoptimized + debuginfo] target(s) in 1m 26s                                                                                               
   Uploading lammps-sys v0.5.0 (/home/lampam/cpp/other/rust/lammps-sys)

But it also does most of this (except the final upload) if I use cargo package.

I feel like I must be going blind, but… is there not an option in cargo publish that lets me tell it to upload an existing .crate file created by cargo package?