TUCSON, Ariz. — The Colorado Rapids engineered one of the more remarkable turnarounds in league history last season, improving on last-place and second-to-last finishes in 2015 and 2014, respectively, to become one of the top teams in Major League Soccer.

A runner-up in last season’s Supporters’ Shield race, Colorado are now faced with the important task of trying to sustain that success. Head coach Pablo Mastroeni’s men were dominant on the defensive side of the ball in 2016, and will need to produce similar results this year, unless they can figure out how to put some more goals on the board.

The Rapids posted the top defense in the league in 2016 by a long shot. They were the only club to allow less than one goal per game. And even in the 16 games games before goalkeeper Tim Howard’s arrival, they allowed a stingy 11 goals.

After a 3-1 preseason win over New England on Saturday, Mastroeni told MLSsoccer.com that last season's turnaround is the first step to becoming a perennial force.

“I think the one thing going into this year is that we’ve built a pretty good foundation of the way we want to play and the way we want to approach the games," he said. "We’ve developed a good mentality within the group, and brought back a core group of the guys as well. I think that’s what’s different from last year to this year.”

Asked if he would lean on defense again in 2017, Mastroeni acknowledged the success afforded to his team was due to its staunch defensive mindset. But he insisted that the Rapids are focused on improving the attack, as well.

“When we don’t have the ball we want to be the best defensive team," the Rapids coach said. "And when we have the ball we want to be the best attacking team. The defensive mindset of the group is the foundation of what we’re doing, because there’s always an understanding of how we’re going to win the ball back when we don’t have it.”

There's certainly work to be done in the attack, as the Rapids registered just 39 goals last season, tied with the Houston Dynamo for second-worst in MLS. Mastroeni has brought in help on that front, adding MLS veteran Alan Gordon and 22-year-old Ghanaian midfielder Bismark “Nana” Adjei-Boateng.

Mastroeni called Adjei-Boateng an “attacking, forward-looking” player in the midfield, and said his pair of acquisitions "bring a great deal of depth to the group" and "gives us a lot of different options in the attack."

With more depth up top, Mastroeni finds himself with the luxury of moving Kevin Doyle around. Asked about Doyle’s role this year, the Rapids boss acknowledged that Doyle and Dominique Badji have each played the No. 9 position this preseason, and said there's a “possibility” that Doyle could play again at the No. 10, something the Irish attacker did near the end of last season.

“Having the ability to play Doyle in a couple of different positions with Gordo up front is good to have in your arsenal,” Mastroeni said.

Colorado wrap up the Desert Diamond Cup on Saturday before opening MLS play March 4 at home against New England (6 pm ET, MLS LIVE).