Who will replace Rob Johnson on Cardinals roster once Yadier Molina is healthy?

In a somewhat surprising move, but one that was long overdue, the Cardinals release Ty Wigginton and called up catcher Rob Johnson from AAA Memphis.  Johnson is needed as Yadier Molina is banged up and the Cards need an extra catcher for insurance.

However, this is only a temporary assignment for Johnson, as once Molina is healthy, its likely that Johnson will be sent back to AAA.  This begs the question as to who will replace him on the active roster?

Here are the two leading candidates:

Ryan Jackson

Jackson is currently hitting .301/.378/.399 at AAA Memphis and is probably a better defensive short stop than Pete Kozma.  With Kozma's recent struggles at the plate the Cardinals could call upon Jackson to give Kozma some extra rest.

In addition, Jackson has some versatility, having played second, third and some outfield in the minors this year, as it appears the Cards are grooming him to be a utility player.  Adding him to the roster would give the Cardinals a better defensive backup to Kozma at short than current backup Daniel Descalso, plus another right handed bat off the bench.

Brock Peterson

At age 29, Peterson is not a prospect anymore, but he is hitting .308/.381/.563 with 20 homers at AAA. He could give the Cardinals some extra pop off the bench and another right handed bat to help combat the team's struggles against lefties.

He is not quite as versatile as Jackson, but can play first, second, third and the corner outfield spots.  He has spent 11 years in the minors, but has never reached the majors. He was also recently named to the PCL All Star team.

I think one of these two will be called up after the all star break to replace Johnson on the active roster.  Of course, the Cardinals could always cross us up by calling up another reliever or someone like Adron Chambers, but my guess is that Jackson will get the call.  He gives the Cardinals what Ty Wigginton should have, at a fraction of the cost.