I went to a baseball autograph database (http://www.baseball-almanac.com/automenu.shtml); then I wrote a script that would hide all players that didn't play during the time frame in question. (I even granted several years leeway both ways).
Then I looked at the autographs of everyone (A-Z, both leagues) who had an I or J in their last name. I may have missed some, because that part I did by visually scanning the page ( there are quite a lot of players from that time frame ). The only player who I thought was even close was Todd Zeile, and he wasn't all that close.
If anyone is interested I can post the script here, and you can try what I did. For now however; I am (with much regret) concluding that there is something being overlooked in the OP's memory.
Could it have been a Spring Training game (and the signer a minor leaguer who didn't make it to the show in that time period)? Maybe a coach who was a former player; and the OP remembered it that way? Worse -...