The 28-year-old Upton is the most powerful of the free-agent centerfielders unless you consider Josh Hamilton more of a centerfielder than a leftfielder. Upton is also a righthanded hitter with speed who plays solid defense. He is the youngest of the elite free agents, too, and the one most closely linked to the Phillies at this point.
But with Michael Bourn, the switch-hitting Angel Pagan, and former Phillies centerfielder Shane Victorino still on the market, there would be no reason for Amaro to panic if the team fails to sign Upton.
Like Upton, Bourn rejected a $13.3 million qualifying offer from his former team, so if the Phillies sign either of those players, they will lose their 2013 first-round draft pick.
Bourn, who will turn 30 next month, is the best defensive centerfielder and most prolific base-stealer of the group. Victorino's career .341 on-base percentage is the best among the four, but at age 32, he will be the oldest of the four next season. He also is coming off his worst big-league season. Pagan, 31, is coming off one of his best seasons, having helped San Francisco win the World Series.
The Phillies would not lose their first-round pick if they signed Pagan or Victorino, and both players figure to be more affordable than Upton and Bourn. If the Phillies opt for a cheaper option in center field, they could turn their attention to adding power at one of the corner outfield positions.
The emergence of Darin Ruf as a power-hitting possibility for next season has given Amaro some flexibility as he pursues free agents and conducts trade talks. Ruf, 26, completed his stint in Venezuelan winter ball after hitting 10 home runs and driving in 27 runs in 32 games.
"We learned that he can play an adequate left field, right field, and first base," Amaro said. "We also learned that he has quite a bit of power, but we already knew that.
"Darin Ruf is not going to be handed a job in spring training, but he's certainly going to be in the mix."
What about Domonic Brown?
"I'm not saying anybody is going to be handed a job, but Brownie has more of an inside track because he has a little more experience and because of his potential," Amaro said. "But nothing is etched in stone."
Notes. The Phillies signed righthander Brandon Erbe, 24, to a minor-league deal. . . . Third baseman Cody Asche, a Phils farmhand, was named to the Arizona Fall League's top prospects team, chosen by managers and coaches.
Contact Bob Brookover at firstname.lastname@example.org. Follow @brookob on Twitter.