Birmingham City have been sitting in the Championship for a long while now, and in that time they've seen a lot of players come and go.

In the 21st century, the Blues have played in England's second tier for 14 of those seasons, and they've not been in the top flight for 10 years now.

Being in the Championship for that long you can somewhat forgive their transfer dealings for being hit and miss, especially when some managers were given lots of funds (like Harry Redknapp) and others not so much.

Some of those have been shrewd acquisitions, but others have been far more forgettable - especially those loan deals where players make just a few appearances before disappearing off the face of the earth.

Let's take a look at 11 former Blues players that you may have completely forgot played for the club during their career, all of whom have been at the club between 2007 and 2017.

Halford is one of the quintessential journeymen of the Football League that has seemingly played for half the clubs that have either been promoted to or have been vying for a Premier League place in years gone by.

The versatile defender surprisingly linked up with the Blues in November 2015 on loan, just a few months after joining Rotherham United, but not long after joining the club he was dropped by manager Steve Evans.

He made three substitute appearances in his loan spell before returning to the Millers two months later - not one of Birmingham's more successful transfer deals it has to be said.

Aluko is now getting to the twilight of his career, but you'd have to say it's been a successful one as he's been a good Championship player for the majority of it.

Once upon a time though, Aluko was a fresh-faced teenager trying to make it into the first-team at Birmingham City.

It never quite happened for the attacker though. He was named as a substitute for a Premier League game in 2005 as a 16-year-old, but his sole Blues appearance came in a 2007 League Cup tie against Hereford before joining Aberdeen on a permanent deal a year later.

It was Stoke City that took a punt on Shea in 2013 for £2.5 million, and it was one that didn't particularly end up working out for them.

A year and a half into his stint at the Potters, Shea joined Birmingham on a short-term loan and made six appearances for them, but the deal wasn't extended beyond his initial stay.

Even though his spell in England didn't do him any favours, Shea returned to the USA not long after his spell at the Blues was finished and he's been a regular several MLS clubs, but he just wasn't a good player for Birmingham.

Another unsuccessful Blues loan deal, Allan joined as a 21-year-old from West Brom in 2013 having had minimal senior football experience in England.

It was always going to be a learning curve for Allan and he had a tough time of things at St Andrew's, and after appearing in three of the first five league games he didn't make a matchday squad between September and mid-April.

Allan returned for two of the last three Birmingham games of the season, and since that spell he's gone on to be a bit of a success north of the border at Hibernian, whilst also securing a big move to Celtic in 2017 that didn't work out.

In what seemed a bit of a bizarre signing at the time, Birmingham took Honduras international Costly on loan from Polish side GKS Belchatow in 2009 for the rest of the season.

Costly had scored five goals for his country before joining the Blues so there was understandably some expectation on his shoulders - the tall striker though failed to live up to it.

Costly made just eight league appearances for Birmingham without finding the back of the net, and following years has seen him play in the likes of Greece, China, Mexico and Turkey - a real globe-trotter.

Birmingham took a Danish striker on loan 2006 to try and get them back to the Premier League - his name was Nicklas Bendtner - and his performances and goals led to the Blues returning to the top flight.

Nine years later, the Blues took a punt on another Dane as they searched for a prolific goalscorer, and they landed on Brock-Madsen, who hadn't exactly pulled up any trees goal-wise in his home nation.

Birmingham fans' worst fears were proven as he went on to make just six league appearances for the club, all in his first season in the Midlands, and he then went on to spend the next three campaigns out on loan before departing permanently in 2019.

Lita was a prolific scorer in his early career for both Bristol City and Reading, but following his departure from Middlesbrough in 2011 his goals began to dry up.

Premier League side Swansea took a punt on Lita in 2011 but he quickly found himself out of favour, and the following season he made a loan move to Birmingham for three months.

Lita netted three times for Birmingham before his loan was cut short due to a thigh injury, and it's safe to say that his career soon took a little bit of a down-turn, as within a couple of years he was in the lower reaches of the Football League.

Birmingham took advantage of a precarious situation at Portsmouth in 2012 by taking striker Huseklepp on loan from the administration-stricken club for the rest of the season.

Having scored six goals in the Championship that season for Pompey, the Norweigan was expected to come in and make an impact, but he was mainly restricted to substitute appearances for the Blues.

He did though manage to score twice in 11 league outings, a respectable tally for someone that wasn't allowed many minutes.

Huseklepp returned to Norway the following season and he remained in his home country for the rest of his career.

Probably now best known for his stint at Celtic where he helped them to multiple titles, Sinclair spent a lot of his early career out on loan in the Football League.

Sinclair's 2009 move from Chelsea to Birmingham was his fifth loan deal in two years, and he made 14 league appearances for the Blues without scoring.

Whilst his stint at St Andrew's may have been forgettable, his career following that wasn't as he starred at Swansea which got him a move to Man City, but he also ended up starring for their biggest rivals in Aston Villa.

After two double-figure scoring seasons in the Championship for Luton Town, Birmingham snapped up Vine for £2.5 million in the middle of the 2006/07 campaign, with the striker netting 12 times in 26 outings before his move.

Vine couldn't transfer his success in-front of goal from Kenilworth Road to St Andrew's though. He did make 17 appearances between his signing and the end of the season but scored just the once, and he was never in the club's plans for their Premier League season in 2007/08.

A loan move that turned into a permanent switch to QPR followed just nine months after he had joined Birmingham, with the club recouping £1 million of the money they paid for him.

Rusnak was another one of Birmingham's forgettable loan spells of the mid-2010's, initially joining for a month from Manchester City and then it was extended until the end of the season.

City will have wanted the Slovakian to gain match experience, but he got little of that as he made just four appearances in all competitions.

To be fair to Rusnak though he was clearly talented, as he went on to play regularly for Groningen in Holland's top flight before moving to MLS side Real Salt Lake, and he's also made 28 appearances for his country.