On 'The Unusuals', Detective Jason Walsh confessed to his new partner (Detective Casey Schraeger) that he threw a few games while he was a pitcher in the minors. But that when he finally joined the Yankees in "the show" at the age of 22, he balked at doing it again. In retaliation, some mob gambler may have had Walsh's girlfriend wacked.
It's common practice for Toobworld Central to assume that a TV character is the same age as the actor who plays him or her - unless specifically mentioned in the script. (Not that they were born the same year, of course - too many shows take place in the past and the future!)
So Jason Walsh is the same age as Jeremy Renner - both are 38. This means Walsh's career with the Yankees began in 1993. (No idea how long his career - no matter what teams he played with - lasted, however.)
Here in the real world, the 1993 roster for the New York Yankees included these pitchers:
That's a lengthier list than I thought I would find. Plenty of names there to make it easy enough to slip in an extra man on the mound for Toobworld. It's a practice that happens all the time with the Television Universe. Look at all the fictional characters who were on the Titanic, or in the World Trade Towers on 9/11.
Of course, this all depends on whether or not Walsh was telling Schraeger the truth. And the jury's still out on whether or not he can be trusted....