Right now the five backups are Knapp, Blanco, Stassi, ???, ???.
I figure Stassi makes it as a defensive replacement, LH pinch hitter, and they'll try him in LF to add a LH bat.
Since Kendricks can play 2B, and Blanco SS/3B, and they'll have IFs at Lehigh who can step in, the focus will be on two OFs.
Knapp is the backup catcher unless they add a veteran.
I doubt Quinn or Goeddel will start with the team in April, they will want them in Lehigh getting PT.
Pullin is a long shot but a hot spring could win him a backup job, since they probably don't see him as a future starter they'd be less worried about setting his development back.
Nava, Shaffer are longshots, Nava would have to show he's all the way back, and Shaffer is someone they'd probably prefer to work with in AAA than bury on the bench. Though he did start 25 games in the OF in AAA last year - that's his ticket to stick with the big club.
I see them adding at least one FA OF once the prices go down in FA (i.e. someone is willing to sign a 1-2 year deal).