The pair joined Senone, a team of investors featuring former Dragons' Den star Theo Paphitis and led by Ian Currie, former director of Bolton Wonderers, which focuses on investing money in smaller companies which have been turned down for financing.
Clearly, representing England in the two most popular sports in the country isn't enough for Rooney and Pietersen, who have so far invested funds in more than a dozen of the country's SMEs and saved around 200 jobs.
Currie told Smarta "Senone is a partnership we set up after seeing what the market was like. We invest in smaller companies and look for businesses which are growing and profitable but cannot get financial support. We look for decent management as well, simple as that."
The partnership also has a focus on "spending months getting to know businesses and people" before financing is agreed.
This departure from computer systems which may rule out certain backing applications has been reaping rewards as Currie mentioned each business he is involved with "is on or ahead of plan", showing viable businesses are struggling to find support elsewhere.
So far, a printing firm, a petrol forecourt business, an interior design company and a luxury motor homes business have ranked amongst the businesses to benefit from the investments.
The opportunities seen by Senone has driven Ian Currie on a quest to extend the idea and start his own bank, taking public deposits and using them to invest in British businesses, but this is only in the early stages of progression, as regulatory backing will be needed.