With the countdown to spring training in its final stages, we're counting down the five biggest storylines facing the Nationals in Viera. We continue today with spring storyline No. 4: The changed dynamic in the Nats' clubhouse...

As cohesive as they appeared to be on the field, the 2012 Nationals were equally cohesive in the clubhouse. You can argue whether good chemistry breeds winning or whether winning breeds good chemistry, but either way the Nats were a close-knit, jovial group last season en route to the franchise's first-ever division title.

The group that convenes in Viera, Fla., next week, while featuring mostly familiar faces, will nevertheless include a few prominent new players while lacking a few highly popular former players. Which leads to at least some uncertainty about the dynamic inside the clubhouse of a team that will draw tons of attention this year.

That's not to suggest that anyone expects dissension within the clubhouse. Mike Rizzo nearly always touts a player's high character upon acquiring him, and the general manager has rarely (if ever) been proven wrong in the four years he's been on the job.

But the Nationals personnel changes will be obvious this spring, perhaps most notably with the absence of left fielder Michael Morse, traded back to the Mariners last month. Morse was among the most popular players on the roster the last two seasons, the unofficial clubhouse DJ and happy-go-lucky slugger who always had a smile on his face.

Rizzo essentially wound up swapping Morse for Denard Span, the only real change to the Nationals' projected Opening Day lineup. Span arrives from Minnesota with a solid reputation himself, a well-liked member of the Twins for five seasons. It will be interesting, though, to see how long it takes for the speedy center fielder to feel at home in his new surroundings, given his lack of previous connections with current Nationals players and the fact he had never even faced Washington in his career.