Put somebody out to grass
Definition 1 of 2
Pro Tip 1/3Forced Retirement
This phrase suggests someone is being retired involuntarily, not by their own choice. 
Though he loved his job, the company put Robert out to grass.
Pro Tip 2/3Discreet Dismissal
May imply a subtle way of removing someone from their role without a direct dismissal. 
Instead of firing her, they just put her out to grass.
Pro Tip 3/3Negative Sentiment
Can convey a negative feeling as it is undervaluing someone’s ability due to age or change. 
His colleagues felt it was unfair when he was put out to grass.