Mauro Rosales immediately made an impact in Seattle's 2-1 win vs. San Jose
Getty Images

POLL: Which offseason signing will work out best?

It's been one of the busiest offseasons in MLS history, with teams at each end of the table – and most of them in the middle, as well – adding players all over the pitch.

Sometimes those moves work out. Just take a look at some of the difference-makers we welcomed to the league in 2011:

  • Mauro Rosales, Seattle Sounders – The Argentine maestro was in the running for league MVP until a series of late-season knee injuries derailed his campaign. He was the Newcomer of the Year nonetheless, and big things are expected in 2012.
  • Robbie Keane, LA Galaxy – LA beat a host of Euro sides for Keane's services, and while he didn't set the league afire upon his arrival in August, the Irishman made some crucial plays in the CCL and served up the game-winning assist MLS Cup. He's among the Golden Boot favorites this year.
  • Danny Koevermans, Toronto FC – Also among the Boot favorites, Koevermans is a brilliant No. 9, perfect for the middle of the front three in Aron Winter's 4-3-3 up in Toronto. In 10 league games, he bagged eight goals and added an assist while helping TFC to the CCL quarters.
  • Torsten Frings, Toronto FC – While Koevermans provided the punch up front, it was Frings who ran the show and really turned Toronto's season around. Whether it was as the back point in the midfield or sweeping in the 3-4-3, the German's presence was crucial for Winter's men.
  • Pável Pardo, Chicago Fire – Consensus was that Pardo was washed up when he arrived. It took about 10 minutes for him to show that wasn't the case, driving the Fire to the US Open Cup final and to within a hair's breadth of the playoffs over the next three months.
  • Sebastián Grazzini, Chicago Fire – Grazzini, who's built in the mold of countryman Javier Morales, became the attacking hub for the Fire, sitting right behind the strikers and creating magic with nearly every touch.
  • Luke Rodgers, New York Red Bulls – The little Brummie had questionable bona fides heading into the league, but proved to be invaluable. The Red Bulls went just 1-4-9 without their spark plug, and his return elicited a collective sigh of relief among the New York faithful.
  • Faryd Mondragón, Philadelphia Union – And like that, he was gone. While the Union have confidence in new No. 1 Zac MacMath, Mondragón's presence was crucial in stabilizing the defense for the second-year club.
  • Aurélien Collin, Sporting Kansas City – His first few games were disastrous, but by the time Sporting got to Livestrong, Collin had established himself as a rock in the back and a nice, big target on set pieces.
  • Diego Chara, Portland Timbers – Chara took some time to settle in, but by June had proved to be the type of do-everything midfielder that blue collar teams like the Timbers need to thrive. Almost got his expansion team to the playoffs in the ultra-competitive Western Conference in the process.
  • Camilo, Vancouver Whitecaps – It was DP striker Eric Hassli who made headlines through the first few months, but Camilo became Vancouver's go-to guy by the middle of the year. He ended the season wtih 12 goals and the 'Caps' Player of the Year award.

That, of course, is just a sampling of the guys who came to MLS and made a dent.

The other end of the stick are the pieces just don't quite fit. Gaston Puerari and Diego Chaves came and went within a year for the Fire. Kenny Cooper's return to MLS went off with more of a thud than a bang in Portland. Jéferson never lived up to his DP status in Kansas City.

And, of course, there was Mustapha Jarju with the 'Caps. Ouch.

But it's a new year, and with it comes a new haul of big names for fans to pin their hopes on. In come World Cup heroes like Lee Young-Pyo, goal scoring machines like Kris Boyd and veteran backstops like Michael Gspurning. They all have fan bases to please, all have games to win, all have a role to play.

So the question is: Who will play their role best?

Stay connected: The official MLS app keeps you connected with the latest news, highlights, scores, standings, and analysis all for FREE. Download for iOS (Apple) or Download for Android