Vela, Barco and the top MLS newcomers in 2018

The 19-year-old was signed from Paraguayan power Cerro Porteno in the offseason for a reported $3 million, and is expected to immediately slot in for the Lions and help fill the void left by Kaka's offseason retirement. The young designated player is highly regarded and Orlando City hopes he can make a similar impact in MLS as another former Cerro Porteno star: Atlanta United's Miguel Almiron. 

No MLS team has paid as much for a player as Atlanta United did for Barco this offseason, so it's safe to say all that eyes will be on the Argentine teenager in 2018. Barco's $15 million signing was a major coup for the league, as the attacking midfielder had plenty of suitors all over Europe. The former Independiente man can play on the wing or in a No. 10 role, and his addition to an offense already containing the likes of Miguel Almiron and Josef Martinez could make Atlanta nearly impossible to stop. 

The Impact needed a replacement for Blerim Dzemaili this offseason, and they didn't have to look very far. With Dzemaili returning to Serie A side Bologna after his loan expired, Montreal again raided sister club Bologna's roster to sign Algerian international midfielder Taider as a designated player. Taider is highly experienced for a 26-year-old, with 162 career Serie A appearances and 42 caps for his country. If Taider can replicate Dzemaili's production, Montreal will be one step closer to a playoff return. 

NYCFC hopes to strike gold with Medina, a lightning-quick attacker capable of playing several different roles across the midfield or even as a false nine. The 20-year-old has already made his senior debut for Paraguay and, if he continues on his current trajectory, should help NYCFC fans forget about the recently sold Jack Harrison. 

The Red Bulls chased Gamarra, better known simply as "Kaku," for much of the offseason and finally landed their man in February in a $6.25 million deal. The 23-year-old is the first young designated player signing in Red Bulls history, and will be expected to fill the playmaking role that Sacha Kljestan left behind when he was traded to Orlando City. Kaku brings an impressive resume that includes experience with Argentine side Huracan in the Copa Libertadores, as well as three appearances for Argentina at the 2015 U-20 World Cup.

Offense has been an issue for Sporting KC over the past several seasons, and Peter Vermes hopes his side has found a solution in Croizet, a 26-year-old designated player who arrives from Belgian club KV Mechelen. Croizet is versatile and able to play several midfield spots but feels most comfortable in the No. 10 role, which has been vacated by the departure of Benny Feilhaber to Los Angeles FC. 

Vela joins the Dos Santos brothers as high-profile Mexico national team players plying their trade in Los Angeles, but unlike Jona and Gio, Vela opted to join expansion side LAFC instead of the Galaxy. The 28-year-old returns to North America after spending 12 years in Europe and, based on his recent performances for El Tri, Vela still has plenty to give. The former Real Sociedad man is versatile and can play several attacking positions, so LAFC coach Bob Bradley will have a decision on his hands about how to best utilize the Mexican attacker. 

Toronto FC landed a big name to fill their vacant right-back position, but there are questions about how much the former Dutch international has left in the tank. Van der Wiel is still just 30 and should have plenty of good years ahead of him, but he's played sparingly in the last few seasons while bouncing between Paris Saint-Germain, Fenerbahce and Cagliari. If TFC can get something resembling the player who starred for the Netherlands, Ajax and PSG earlier in the decade, it will be a bargain on a targeted allocation money deal. 

Bob Bradley's side snapped up Rossi as one of its first signings, and big things are expected from the 19-year-old designated player. Rossi is already an accomplished scorer at the senior club level, netting 10 goals for Penarol last season to help lead them to the Uruguayan title. Rossi has been capped by Uruguay at the U-17 and U-20 levels, and Bradley will hope the youngster forms a dynamic partnership with fellow newcomer Carlos Vela. 

Sporting KC appeared to pull off something of a coup by signing Gutierrez, a 27-year-old Chile international. Right in his prime, experienced in the top flights of the Netherlands, Spain and Brazil, currently featuring for a strong Chile side, and capable of filling any of the three midfield roles in Peter Vermes's 4-3-3 system, Gutierrez has the resume to become one of his new team's key members right off the bat. 

The Whitecaps got a familiar name with plenty of experience to help bolster their defense, signing Juarez from Liga MX powerhouse Monterrey in the offseason. The 30-year-old was struggling for minutes with Rayados, but Antonio Mohamed's team is stacked and Juarez's lack of playing time doesn't necessarily mean he can't be a key figure for Vancouver in 2018. Juarez brings plenty of experience with the Mexico national team and from European stints with Celtic and Real Zaragoza. 

FC Dallas chased Mosquera for most of the offseason and finally landed the Colombian from Millonarios in February for a reported $4 million transfer fee. The 23-year-old will be expected to help bolster the team's attack from the flanks, and can also move inside to spell playmaker Mauro Diaz. Mosquera will occupy a designated player spot, and FCD hopes his presence will help fill the void left when Fabian Castillo departed in 2016. 

Toronto FC is easily the league's deepest team, but the defending champions are set to incorporate the Athletic Bilbao product into their rotation straight away. Coach Greg Vanney compared Aketxe to last season's breakout star Victor Vazquez, and the the 24-year-old could make a similar impact to his countryman if he can carve out a role to the left of Vazquez in TFC's diamond formation. 

The Fire have not made a huge amount of offseason additions, but Katai should prove crucial as he has been tasked with filling the rather large shoes of the departed David Accam. The Serbian international was acquired from La Liga side Deportivo Alaves, and his performance will go a long way in determining whether the Fire can match their breakout success of 2017. 

Rarely do MLS teams use a designated spot on any kind of a defender, let alone a left back. When that left back also happens to be 19, that signing is going to turn some heads. So it was for the Crew, who landed Valenzuela on a season-long loan with a purchase option from Newell's Old Boys in Argentina. Valenzuela also happens to be an Argentina U-20 international who started two games at the 2017 U-20 World Cup, so he joins the league with higher expectations than your average teenage fullback.