The impression I'm getting from Dombrowski and his regime is that they are not going to waste time with guys like Rusney who are not getting the job done. Farrell has already said he is going to manage with more urgency this year which says to me that they are going to be treating games earlier in the year more seriously, and certain players may have shorter leashes.
What I think that means, is that they will shorten the traditional April and May evaluation period, and go with the hot hand, unlike Cherington's more patient approach (ie more time to Hanley's LF transition).
Obviously it won't affect every position on the field, but certainly the corners and left field, maybe even the catcher position (or *gasp* occasional right handed bats at DH, if Papi starts as slowly. Not advocating necessarily, but could be on the table.). If Rusney blows worse than Sandoval, then I could see Shaw in left and Panda starting everyday at 3rd.