He never wore a Chelsea shirt in a competitive match, but in September 2010, Milan Lalkovic got a squad number.

The Slovakian winger was browsing the club website when he discovered that he had been included in a list of players aged 21 or under who were eligible to be called into Chelsea's senior squad during the 2010-11 Premier League season. His squad number, 64, was the highest the club had ever issued.

A quick, two-footed forward, Lalkovic was spotted by Chelsea while playing for Slovakia's under-15s. Chelsea nabbed him from beneath the noses of Manchester City in December 2006, with the teenager feigning illness as a pretext for missing a flight to Manchester and heading to London instead.

After three years in the youth ranks, he joined the first-team squad for pre-season in 2010 and came on as a second-half substitute in friendly games against Crystal Palace and Ajax. They would be the only first-team appearances he ever made.

"I got on the squad list under [manager Carlo] Ancelotti and I got a squad number, 64. Then he got sacked, so you're starting all over again," Lalkovic told Bleacher Report.

"I had a pre-season under [Andre] Villas-Boas [in 2011], but then I started going out on loan. And you have so many players ahead of you—big players, internationals who cost so much money—so it's not easy."

Lalkovic joined Doncaster Rovers, then in the Championship, on loan in August 2011 and was subsequently loaned out to ADO Den Haag in the Netherlands, Vitoria de Guimaraes in Portugal and League One side Walsall before finally leaving Chelsea—seven years after joining the club—in the summer of 2014. His experience as a Chelsea player represents what has become an increasingly well-trodden path.

Milan Lalkovic playing an FA Cup Youth game for Chelsea Michael Regan/Getty Images

Currently, Chelsea have 42 players out on loan, a list that extends from former first-team players like Victor Moses and Alvaro Morata to up-and-coming prospects such as Mason Mount and Dujon Sterling. The clubs playing host to Chelsea loanees range from AC Milan to Basingstoke Town in the seventh tier of the English football pyramid.

Some of the players out on loan will harbour realistic hopes of returning to Chelsea and forcing their way into the first team, particularly with the club now facing a ban on signing new players in the next two transfer windows for breaching rules regarding the recruitment of young players. But some, like Lalkovic, will eventually leave without ever making the grade.

Croatian goalkeeper Matej Delac was loaned out nine times by the Blues during an eight-year stint at the club before leaving last year to join Danish side AC Horsens. The 26-year-old had become Chelsea's most long-serving player, yet he departed without having made a single competitive appearance.

Colombian forward Joao Rodriguez has followed a similar path. When the 22-year-old joined Spanish second-tier outfit Tenerife last summer, it was his ninth loan move in just five years.

Chelsea's use of the loan system has attracted strong criticism in recent years. Its detractors have ranged from Gary Neville and Sam Allardyce to former Stamford Bridge loanees like Kevin De Bruyne and Patrick van Aanholt.

Even current Chelsea players have spoken out against the club's loan policy. Speaking to the Daily Mail in 2016, Brazilian forward Lucas Piazon (now at Chievo in his sixth loan move in six years) said it made "no sense" for players to repeatedly go out on loan and it was "not good for any player."

Chelsea could soon be forced to rethink the way they make use of their fringe players, amid reports that FIFA plans to restrict the number of players that clubs can loan out each season.

But in the eyes of some of the current members of Chelsea's loan army, going out on loan remains the best way to prove you are ready to make the step up to the first team.

"From when I joined Chelsea to now, going through and seeing all of it, being there when they won the Champions League, the Europa League, the FA Cups, you think, 'I want to be able to do this myself one day,'" Chelsea goalkeeper Jamal Blackman told Bleacher Report.

"That's what drives everyone. You want to be able to play for such a big team. You want to get as much experience as you can, so you want to go on loan so you can show people you're ready to play for the Chelsea first team."

Jamal Blackman SAEED KHAN/Getty Images

The club's loanees are supervised by a three-man management team made up of former Blues Eddie Newton, Paulo Ferreira and Tore Andre Flo. The trio provide feedback on the performances of the on-loan players, take responsibility for their general wellbeing and liaise with the coaching staff at their respective clubs.

Croatian striker Stipe Perica was loaned out to Dutch club NAC Breda and Italian side Udinese by Chelsea, but says he never felt abandoned by his parent club.

"Paulo Ferreira would come and watch me," recalled Perica, who joined the Serie A team on a permanent basis in 2016. "He'd watch my games and then send me [footage of] my games on email, telling me what I needed to do better and what I needed to improve. And every time, he'd ask me what I needed.

"I was never a first-team Chelsea player, but I was really happy with their programme. I really appreciated being a part of the club."

Blackman, 25, is recovering from a broken leg he suffered while on loan at Leeds in November. The former England under-19 international, who has also spent time at Middlesbrough, Swedish side Ostersunds, Wycombe Wanderers and Sheffield United, says Chelsea's loanees are made to feel that they remain part of head coach Maurizio Sarri's plans.

"Eddie Newton, Paulo Ferreira and my [goalkeeping] coach, Christophe Lollichon, go to all the games and then feed back to the manager, so he knows how we're doing," said Blackman, who joined Chelsea at the age of 12.

"We're quite lucky. You never feel like you're left out in the dark. You always feel like if you perform well, people will see it."

Former Chelsea star Paulo Ferreira is among those checking on the players out on loan Pete Norton/Getty Images

There is a shared sense of purpose among Chelsea's loan contingent that is reinforced by the club's famous loanees' WhatsApp group, which is where players and coaches from the loan department share information with each other and offer support.

"It's quite chilled. It's like a normal group chat," Blackman said. "We all check on how each other's doing and we get to see each other's clips that get put in. You praise people when they're doing well and just try to let people know that we're all there together, doing the same thing, trying to show what we can do."

As much as the support network put in place by Chelsea is designed to help players thrive while they are away from the club, a loan move remains a test of a player's ability to stand on his own two feet.

Lalkovic admits that he struggled during his spells at Den Haag and Vitoria, refusing to accept his status as a fringe player, but with the benefit of six years' hindsight, he knows the experiences played a crucial role in his development.

"My attitude towards training probably wasn't as good as it is now," says the 26-year-old, whose accent betrays the years he spent in London during his formative years.

"Because I thought, 'If I'm so good in Chelsea's reserves, why am I not playing here?' I just gave it up. I thought, 'If I'm not playing, why should I train hard?' Then you're just killing yourself. It's sulking, it's stupid. It's a young boy mentality.

"I wish I'd had this head on my shoulders back then, when I was 19. But you learn from your experiences, even the bad ones, and when you look back now, you're stronger. You know how to handle yourself."

Click to expand figure....

Lalkovic eventually found regular first-team football during a loan spell at Walsall in England's third tier. After leaving Chelsea for Czech side Mlada Boleslav, he came back to the United Kingdom in 2015 and played for Barnsley, Walsall (again), Portsmouth and Ross County before returning to the Czech Republic with Sigma Olomouc in 2018. Looking back on his time as a Chelsea loanee, he says he has "no regrets."

Blackman has no time for the criticism that Chelsea's loan policy has received. He argues that at a time when a lack of opportunities for young English players in the Premier League remains a major source of concern, anything that allows players to accumulate competitive experience should be applauded.

"I don't see what's so wrong about players being on loan," he said. "If you look back down the line, you see a lot of ex-Chelsea players playing in the Premier League.

"You've got your Ryan Bertrands, your Patrick van Aanholts who are doing well in the Premier League. You see that Chelsea are still producing players, and even if it's not for Chelsea, it's still for other teams.

"Everyone in the football community wants players to be able to play. Going out on loan is a good thing because it enables you to do that."