AMSTERDAM — With preseason camps starting all across Europe, it's time to take a peek at the progress made by some of the young Americans working their way up club ladders in Europe in search of a first-team breakthrough.

Here's a look at five potential future US national-teamers who have yet to make their first-team debuts for their clubs. (For our purposes, we've omitted equally promising players like Molde FK defender Sean Cunningham and 1860 Munich attacker Bobby Wood, who have already debuted). They are ranked here in order of how soon their breakthroughs could be coming.



5) Charles Renken (Hoffenheim)



While the 17-year old props up our mini-table here, he'd be a threat to top it if we went by the potential for excitement generation this season. Knee injury woes in the rearview mirror, Renken is again competing well above his age level with a second-team promotion.



"He's been with the Under-23s since January," Hoffenheim press officer Marcel Kamm told MLSsoccer.com. "He has no [injury] problems anymore. He's been playing the right in a 4-2-3-1 in the preseason."



Smoothly inventive on the ball, the diminutive Renken has a ways to go before we start sizing him up for a locker stall at the Rhein-Neckar. Still, this could be a season where he regains the title of "Next great hope" for USMNT fans.



4) Jared Jeffrey (Mainz 05)



Finally fit after a long hernia bout that dragged on longer than it should have due to an initial misdiagnosis, the former U-17 and U-20 World Cup regular finds himself in a familiar place. Jeffrey is with Mainz's first team in preseason and trying to impress a boss that is as eager in awaiting his breakout as are stateside fans.



Make that a second boss now. Jeffrey, 21, started all of his Club Brugge campaign like he has started each of his Mainz preseasons, yet still remains in wait of a first-team debut.



Despite the task of cracking a strong central midfield corps on a team bound for the Europa League, that debut may actually come this time.



"Unfortunately, Jared has had to deal with a long-lasting injury last season and had to sit out for quite a long time," Mainz II manager Manfred Lorenz told MLSsoccer.com. "But we believe that due to his strong playing abilities, he will have a chance to get to the top if he manages to further improve his defensive skills."



3) Alex Molano (Dinamo Zagreb)



A player often overlooked due to playing in Croatia, the 19-year-old playmaker could be ready to demand some attention after splitting last season between the Dinamo academy and second team. Capable of taking the keys in the middle or working from the wing, the attacker is now ready to begin knocking on the door of what is probably the toughest first team to crack in Eastern Europe.



"He does have some [flaws] and needs to go through a patient process, but he does have big potential," Blues youth director Romeo Jozak told MLSsoccer.com. "It's very competitive in the youth in Croatia and he keeps up. It's tough [to break into the first team], but he's getting there. He's one step away."



Though not invited to first team camp to start the new season, the executive says Molano will play in the reserves for now — in case he is needed later in the event of a selection crisis.

"He's close," stated Jozak. "It's possible."



2) Will Packwood (Birmingham City)



It probably escaped the notice of most fans when the lanky defensive midfielder inked his first pro deal this month after working his way up the club ranks for three years. With the Brums going down to the Championship and Packwood's burning star on the rise, his career path won't stay a secret for long.



"Will is the hardest-working young man I've ever worked with," Birmingham Reserves manager Richard Beale told MLSsoccer.com. "He has a passion and a level of commitment which surpasses the majority of young players in his age group, and that gives him a great chance.



"He is improving week on week and becoming a more complete player. He still has a lot to do to become a first-team player here at Birmingham, but he is held in high regards."



Packwood will open the season with the second team, but should spend plenty of time training with the first team and could even go on loan for that pro debut. Beale says the 18-year-old has enough in his locker to enjoy that memorable graduation day this term.



"As a central midfielder, he is in a very competitive position but he can also play [center back] and that gives him flexibility," said the coach. "It's a big year for him here at Birmingham City. With a new manager in place in Chris Hughton, he must keep working hard to impress. But I've got no doubts he'll do that because he is an extremely focused young man."



1) Joseph Gyau (Hoffenheim)



The 18-year-old winger (pictured at top right) has returned to the Hoffenheim second team after beginning the campaign filling numbers with the Bundesliga side.

"Joseph is a talented and viable player," manager Holger Stanislawski told MLSsoccer.com. "Like other youth players, we are planning to acquaint him to the professional team. At first, he is going to be employed at our U-23 team."



Be that as it may, there's a chance the American could be closer to the first team than we think. Gyau reportedly struck up a good connection on the field with pricey 2010-11 underachiever Ryan Babel and displayed a dribbling style that might more resemble a football running back.



All that and more could actually see him added to the first team's preseason trip roster, though the decision will not be made for a few days. This baby bull may not yet be done with his debut charge.

Honorable mentions: Sebastian Lletget (West Ham United), Alfredo Morales (Hertha Berlin)