A look at the Seattle Sounders' resume through their first three years in MLS suggests a team that has enjoyed outstanding success. After all, winning three US Open Cup titles is something no MLS team had ever done. As impressive as that accomplishment is, however, there is still the lingering feeling that the Sounders have underachieved.

Seattle has boasted one of the strongest teams in MLS over the past three years, but their quality soccer has produced zero playoff victories. Competing in the brutally tough Western Conference has played a part in that, but as the Sounders enter their fourth season, they enter it with a clear mandate:

It's time to make a deep playoff, if not a championship, run.

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As much attention as LA Galaxy received this off-season, the Sounders have had a strong winter of their own. They have brought back all their key players (including Mauro Rosales and Alvaro Fernandez), added former US national team striker Eddie Johnson, and are on the verge of welcoming back injured midfielder Steve Zakuani.

The result is a roster with attacking talent that may actually be stronger than the one that led MLS in goals scored in 2011. Mauro Rosales took the league by storm in his first season and is poised to have another MVP-caliber campaign. His presence as a premier playmaker made everyone in Seattle's offense more dangerous and did wonders for Fredy Montero, who remains one of the league's most dangerous strikers.

The key to whether the Sounders can actually be more dangerous is Johnson, who returns to MLS after a disappointing run in Europe. Johnson may have endured his share of troubles across the pond, but the fact remains he is still capable of being a productive MLS striker. He is still just 27 and is just a year removed from scoring goals in the Greek Superleague. A highly-publicized failed move to Mexican side Puebla, which came after a well-publicized failed return to MLS, tarnished his reputation and raised serious questions about what he could still contribute.

Those issues led Johnson to sign with MLS at a cut-rate price of $100,000 - a bargain for a player who could wind up being a double-digit goal-scorer (he scored 14 goals for Kansas City in 2007, his last season in MLS). Sounders head coach Sigi Schmid is clearly a believer in Johnson, as evidenced by his willingness to trade away promising attackers (and fan favorites) Lamar Neagle and Mike Fucito.

One of the biggest mysteries surrounding the 2012 Sounders is the status of Steve Zakuani, who is still working his way back from the nasty broken leg that cost him most of the 2011 season. While it is still too early to tell how close he will get to returning to his all-star form, the pre-season signs are good. If he can get back to his speedy and dangerous self, the Sounders attack will be almost impossible to stop.

Scoring goals won't be a problem, but the team's ability to keep goals out is going to determine how serious a title contender the Sounders can be. Kasey Keller's retirement left a major void. The legendary goalkeeper's final season was an outstanding one, and he stepped up with plenty of top-class saves to bail out a defense that was weaker than the stats would suggest (Seattle was fourth in goals allowed in 2011).

That defense boasts a solid center back tandem in Jeff Parke and Jhon Kennedy Hurtado, while newly-acquired full back Adam Johansson looks set to take over at right back. With Marc Burch pushing incumbent left back Leonardo Gonzalez and impressive rookie Andrew Duran providing depth at multiple positions, the Sounders defense should be stronger.

The new man in net is Austrian goalkeeper Michael Gspurning, who joins from Greek side Skoda Xanthi. The Sounders are very high on Gspurning, but it will be tough for him to match Keller's level. If Gspurning turns out to be as good as advertised, Seattle will have all the pieces in place for a big year.

Just how big a year? If Zakuani and Johnson regain their old form, and if the defense can improve on 2011, the Sounders have squad to not only win Seattle's first playoff series, but potentially add an MLS Cup to the three US Open Cup titles already in the Sounders' trophy case.

2012 SEATTLE SOUNDERS TEAM OUTLOOK

TOP PLAYERS: Fredy Montero, Mauro Rosales, Osvaldo Alonso, Alvaro Fernandez, Jeff Parke

KEY ADDITIONS: Eddie Johnson, Michael Gspurning, Adam Johansson, Christian Sivebaek, Andrew Duran, Marc Burch

KEY LOSSES: Kasey Keller, James Riley, Erik Friberg

MUST HAVE A BIG YEAR: Michael Gspurning. Seattle's new goalkeeper must be Solid if the Sounders are to be taken seriously as a title contender.

BREAKOUT PLAYER TO WATCH: David Estrada. A first-round pick in 2010, Estrada has yet to play an MLS match, but he's enjoying a strong pre-season and could be a pleasant surprise if he is able to find minutes behind Montero and Johnson.

BIGGEST QUESTION: Which Eddie Johnson will show up? If we see the player who scored 14 or more goals twice during his previous MLS stint, the Sounders will be fun to watch. If Johnson struggles to stay healthy, or worse yet, is a problem in the locker room, the trade that brought him to Seattle will look like a disaster.

OUTLOOK: While it is a safe bet the Sounders will boast the most dangerous offense in MLS, it remains to be seen if Sigi Schmid's squad will have the necessary defensive quality to be a true championship contender. Is things stand, Seattle is definitely in the conversation along with LA and Real Salt Lake, but the Sounders face more uncertainty at key spots than the other two teams. If Schmid's acquisitions of Johnson and Gspurning strike gold, he will stand a very good chance of becoming the first MLS head coach to win MLS Cups with three different teams.