Running command from virtual env in Jenkins pipeline without explicit activation

Question

I use a shell script that, let's assume, I cannot update:

#!/bin/bash
ansible-playbook $1

The script is called in Jenkins declarative pipeline as:

sh "myscript.sh my-playbook.yml"

The pipeline runs on Jenkins node where ansible (2.9) is installed in python (2.7) virtual env. ansible-playbook is hence not available before the virtual env is activated.

Is it possible to call ansible-playbook without activating it in the shell script? I am allowed to do changes on the Jenkins node only.

I tried to create a function in ~/.bashrc (and source it):

function ansible-playbook() {
    source /path/to/my/venv/bin/activate
    command ansible-playbook "$@"
    deactivate
}

It works when called in the shell, but Jenkins pipeline fails on "ansible-playbook: command not found". Is it not the correct approach to:

1. activate virtual env, PATH is updated with local virtual env binaries, including ansible-playbook
2. use command to make bash skip searching for functions and aliases so the function does not call itself in a loop
3. deactivate virtual env

NOTE: sh is linked to bash in my Jenkins node so bash should be executed by the pipeline.