[MLS SPOTLIGHT] The primary MLS transfer window has been expanded three weeks until May 6, so there is plenty of time for MLS clubs to make moves. Up until now, the activity during the MLS transfer window has been rather slow, in part because of the flow of players from Colombia -- a huge source of talent in recent years -- has all but dried up. Still, MLS clubs once again are depending on imports to play key roles. With Nigerian Obafemi Martins' move to Seattle still to be finalized, here is a look at eight imports who could make a difference in 2013 ...

CLAUDIO BIELER (Sporting KC). Just before he scored his first goal of preseason in Sporting KC's final game, Coach Peter Vermes stressed that the Argentine forward was still getting used to the SKC system and learning his role. No doubt, his job will be to score goals. SKC is counting on Bieler being the missing piece it needs to win a title. He scored 20 goals last year for Liga de Quito in Ecuador.

DIEGO CALDERON (Colorado). The 26-year-old defender also comes highly rated from Liga de Quito. He has played five times for the Ecuador national team. The Rapids certainly need help on defense after conceding 50 goals last season. He'll team up with Drew Moor in the middle of the backline, allowing Marvell Wynne to shift back to the outside, the position at which he started his MLS career.

CARLO CUDICINI (Los Angeles). You can't say the Galaxy is resting on its laurels after winning back-to-back MLS titles. Some question whether the 39-year-old Italian has what it takes after being a backup much of his career in England, but he'll be an improvement on Josh Saunders.

GLAUBER (Columbus). The Crew brought in the Brazilian defender from Rapid Bucharest in Romania, Argentine Matias Sanchez and Uruguayan-American Agustin Viana. Glauber could be the difference in getting the Crew back to the playoffs if he can stabilize the backline. He showed glimpses of his potential during the Crew's strong preseason campaign.

JUNINHO PERNAMBUCANO (New York). On the surface, no signing would appear to have been a bigger gamble than that of the 38-year-old Brazilian, who played his best years with Lyon in France. But he instantly becomes the league's best free-kick specialist -- no disrespect to Houston's Brad Davis -- and is, according to Red Bulls coach Mike Petke, a "pleasure to watch." Juninho won seven straight French titles with Lyon, and Red Bulls' fans would be happy if he brings one to New York. “I’m beginning the 20th year of my career," Juninho says, "and I want to do now the same as I’ve done in my first 19, which is to do my very best to help the teams I played for win titles."

ANDREA PISANU (Montreal). Pisanu should fit right in with the Impact's core of Italian players. Bernardo Corradi got the Impact in touch with Pisanu, and Marco Di Vaio played with Pisanu at Bologna. Pisanu convinced the Impact to take him on loan after he played with it against Fiorentina on its fall tour of Italy and he followed that up with a strong preseason at the Disney Pro Classic. He could be the attacking element on the wing the Impact lacked last season.

NIGEL REO-COKER (Vancouver). After half a season, the Whitecaps parted company with Scottish international Barry Robson. They believe Reo-Coker will be a better fit in midfield. Reo-Coker, 28, says he is a very simple guy, not the "angry man" he has often been portrayed as. He describes himself as a "box-to-box midfielder" but says he can say fill in at right back. Reo-Coker, whose wife is American, says he's ready for the grind of MLS. "At the end of the day," he says, "it’s about being professional and making sure you prepare yourself correctly for games and that starts with the whole week."

DIEGO VALERI (Portland). The Timbers think so much of Valeri that they passed on Reo-Coker, on whom they had made a discovery claim, just as they passed on Mix Diskerud. The Argentine showed off his bag of tricks to Jeld-Wen fans at the Portland Preseason Tournament, and he could become the best playmaker in MLS, just the player the Timbers' young frontline needs.

(Check out Soccer America here on Google+).