In 2003 Jacobs received the Sterling award as the top prospect in the Mets farm system, he originally was a catcher but tore his labrum in 2004 which caused his move to first base.
He made his major league debut in 2005 with the Mets and spent his entire major league career as a first baseman.
Jon Heyman tweeted today that Jacobs will have a chance to steal a roster spot from Tatis or Murphy. There was some speculation today that maybe Jacobs could spend sometime at catcher but Ted Berg relays that Mike was not that good at the position...
Not to throw water on this, but last year one of Jacobs' MiLB coaches told me he just didn't have it as a catcher, at all. source Ted Burg twitter
In the minors he played 309 games at catcher and only 81 games at 1B.