MESA, Ariz. -- Coco Crisp was the center fielder for Oakland when Bob Melvin took over as the manager in the midst of 2011.
Crisp is still wearing the green and gold of the A's, albeit in a more limited role as a concession to age and ailments. Melvin is still filling out the lineup card, his 747 games in uniform the third longest in franchise history since Connie Mack's 50-season run ended at the end of 1950, back when the club was in Philadelphia.
Most everything else about the team on the field, however, has changed for the A's, who have seen 120 players appear in a game since the arrival of Melvin.
Two weeks away from breaking camp in Arizona and heading to the Bay Area for their annual end-of-spring three-game exhibition series with the Giants, the A's are looking at a potential 25-man Opening Day roster which will include at least 10 players who weren't around at any point last year, and at least 17, possibly 18, who have a been with Oakland for one full season or less.
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The projected roster will have three, possibly two, products of the A's scouting/player development. Opening Day starter Sonny Gray, a first-round selection in the 2011 Draft, and reliever Sean Doolittle, a first-round selection in '07 Draft, seem set. Ryan Dull, a 32nd-round selection in '12, and Felix Doubront are battling for a bullpen spot.
"We have some turnover here," said Melvin. "We have guys who know how we expect things to be done and they lead the way. Guys like Coco, [Josh] Reddick, [Sam] Fuld, [Stephen] Vogt, [Eric] Sogard. They are guys you lean on."
That's life in Oakland, a team with a small budget, a big history and hopes of finding the pieces to solve the puzzle of a return to the postseason, where the A's advanced in Melvin's first three full seasons before falling into last place in the American League West last year.
Thank goodness for Spring Training. There's a chance for hitters to get their swings in sync, pitchers to build up arm strength and the A's get to know each other on a first-name basis.
"Once the season starts, the guys know how they fit in the clubhouse," said Melvin.
At least they know where they fit for the time being.

What they also know is that executive vice president of baseball operations Billy Beane and general manager David Forst aren't afraid to shake things up. They will make a move with an eye on immediate dividends if Oakland is in contention. They will start unloading with an eye on the future if the club isn't going to be a factor in the race for the postseason.
Looking to win the AL West in 2014, the A's were a focal point in July, acquiring right-handed pitchers Jason Hammel and Jeff Samardzija from the Cubs for three prospects. They also got left-hander Jon Lester and outfielder Jonny Gomes from the Red Sox for outfielder Yoenis Cespedes, as well as outfielder Fuld from the Twins for left-hander Tommy Milone.
The A's had to hold on to claim a Wild Card spot, lost to the Royals in the AL Wild Card Game and began a major overhaul that offseason.
By the start of Spring Training in 2015, Samardzija had been dealt to the White Sox for a package that included starting shortstop Marcus Semien, projected starting pitcher Chris Bassitt and backup catcher Josh Phegley. Third baseman Josh Donaldson was sent to the Blue Jays for a four-player package that included potential starter Kendall Graveman.
Catcher Derek Norris was sent to the Padres in a package that brought back projected starter Jesse Hahn, and in deals with the Rays and Nationals, they wound up with second baseman Ben Zobrist and reliever Tyler Clippard. Neither of those players are still with the A's.
And now, Oakland prepares for 2016 with 10 more expected newcomers, including an infield in which Semien is expected to be joined by first baseman Yonder Alonso, who came from San Diego in a deal involving lefty Drew Pomeranz; second baseman Jed Lowrie, who returned a year after being dealt to Houston; and third baseman Danny Valencia, a waiver claim from Toronto last August.
And then there are left-fielder Khris Davis, a Feb. 12 acquisition from the Brewers; free-agent pitchers Rich Hill, an expected starter, and relievers John Axford and Ryan Madson. They A's also added Liam Hendriks from the Blue Jays in exchange for starting pitchers Jesse Chavez; lefty Marc Rzepczynski, who came with Alonso from the Padres; and versatile Chris Coghlan, acquired from the Cubs.
It's a different look in Oakland. But that is a familiar feeling for the A's.