"I like the steeliness we have in the group, the characters we have. Big personalities," he said. "Certainly if you look on paper, we're a very strong team."
So far, however, the team has been a paper tiger. After a winter makeover in which Arena dumped a third of his roster, the Galaxy managed only one goal in its final five preseason games. It didn't score at all in its two-leg CONCACAF Champions League playoff with Mexico's Santos Laguna, extending its goalless streak to 333 minutes.
That will need to change Sunday, when the Galaxy opens its Major League Soccer schedule against D.C. United at the StubHub Center. And if you listen to midfielder Steven Gerrard, the dismal preseason, combined with last season's early playoff exit, has both united the team and created a sense of urgency.
"Sometimes in preseason you need shocks and setbacks and disappointments to grow and become a unit and come together," he said. "We need a good start to make everyone believe in us."
The Galaxy also needs time, and that may be something it doesn't have a lot of.
Thirteen players on the roster — including seven starters — weren't here for the start of last season. Three of those — midfielder Nigel de Jong and defenders Ashley Cole and Jelle Van Damme — didn't get here until the start of last month. And MLS — with its travel demands, artificial fields and hot, humid summer weather — can be a punishing league for newcomers.
Just ask Gerrard, the former Liverpool and English national team captain who struggled mightily after joining the Galaxy last July.
"Especially for the European guys, it doesn't just happen overnight," Gerrard said. "They're coming into a brand-new environment with new players, new staff, a new way of playing."
That adjustment better not take too long, because the clock is ticking on this team. Keane, Gerrard and Cole are all 35 and in the final year of their contracts. Three other starters will be at least 32 by the end of the year.
So while the talent and experience Arena brought in means this team could prove to be one of the best in MLS history, the trade-off is age, and there this team already ranks among the oldest ever. As a result, the pressure is on to win now, even though Arena, like Gerrard, says it will take a while for all his new parts to learn how to work together.
"In two months we'll have a better feel where our team's at," he said. "But I feel good about this team.
"We have a nice blend of experienced players and some young, energetic players. And good team chemistry. We have to start playing games now and see what we're about. But we have the makings of a good team."
A deep one too. Forward Alan Gordon, who played for the U.S. national team last summer, and midfielder Mike Magee, the league most valuable player in 2013, both figure to start the season on the bench. So will center back Leonardo, the team's defender of the year last season.
Among those starting instead are Dutch World Cup veteran De Jong, a bruising midfielder; Van Damme, a physical defender from Belgium; and Cole, who played more games on the back line for the English national team than any player in history. Arena spent just $1.3 million to sign all three.
In the middle, the Galaxy will get full seasons out of Gerrard and Giovani dos Santos while new addition Emmanuel Boateng on the left wing is among the fastest players in the league.
Among the players shipped out were defender Omar Gonzalez and midfielder Juninho, who both ranked among the top 10 on the franchise list in games played.
So complete was the transformation following last year's late-season collapse, only three starters remain from the Galaxy's last playoff win, which came in the 2014 MLS Cup final.
"When you don't perform, in any team regardless who you are, there's going to be changes," Keane said of a Galaxy team that gave up 10 goals in its final three games last year, en route to its earliest postseason exit since 2008. "So we've made the changes and the players who were brought in [are] top, top players."
On paper anyway. On the field, Arena's busy off-season has yet to pay off. But he's confident it will — if for no other reason than he doesn't want to do that again next winter.
"It's been a very hectic off-season," he said.
Follow Kevin Baxter on Twitter @kbaxter11