Newcastle United have had their fair share of players who have failed to make an impact during their time at St James' Park.
During the Mike Ashley era, the club only really signed players for relatively small transfer fees, in the hope they would impress at the Magpies before making the club a profit should they leave the club.
The 2012/13 season was a prime example, with the Magpies signing nine new players for a combined total of less than £30m.
Moussa Sissoko was the biggest success out of the bunch, with the Frenchman signing for an undisclosed fee believed to be around £2m, before leaving the club for a whopping £30m less than three years later.
However, one player who also arrived at St James' Park that summer failed to make an impact, like Sissoko, with the player now plying his trade in the fifth tier of the French football pyramid.
Mapou Yanga-Mbiwa's stats for Newcastle
French centre-back Mapou Yanga-Mbiwa joined the club for a fee in the region of £7m from Ligue 1 side Montpellier on a deal until the summer of 2018.
He came with a lot of potential, having won the French League title the season prior, but failed to live up to expectations at St James' Park.
Yanga-Mbiwa made 20 appearances in all competitions during his first season at the club, with the defender featuring six times in the Europa League for the Magpies after his January arrival.
21. Rob Elliot
26. Mathieu Debuchy
27. Steven Taylor
13. Mapou Yanga-Mbiwa
3. Davide Santon
11. Yoan Gouffran
4. Yohan Cabaye (C)
7. Moussa Sissoko
24. Cheick Tiote
18. Jonas Gutierrez
9. Papiss Cisse
His first and only full campaign for the club saw him play 26 times under boss Alan Pardew, before leaving the club after a one-and-a-half season stay on Tyneside.
The defender subsequently departed the club for £5.5m, joining Serie A outfit Roma on loan before the Italians triggered the purchase option in the deal.
Mapou Yanga-Mbiwa's stats after leaving Newcastle
His stay in Italy would be a short one, with the 6 foot defender leaving just six months after his permanent move, to join Lyon back in his homeland for a fee very similar to what the Magpies paid for him in 2013.
He enjoyed two successful seasons at the club, featuring 70 times between 2015 and the end of the 2016/17 campaign, including in the Champions League, with Yanga-Mbiwa playing some of the best football of his career.
However, his career would take a drastic turn at the start of the 2017/18 season, with the former Magpie featuring just twice in Ligue 1, before being dropped completely from the Lyon squad.
Yanga-Mbiwa would feature for the club's reserve side between 2017 and 2020 before effectively hanging up his boots and retiring from professional football at the age of just 27 – after not featuring for the club's first team for over three years.
Remarkably, four years after the centre-back left Lyon, he made a shock comeback to football, signing for French 5th-tier side Istres FC, claiming he was "interested" in the club's project.
He's since made five appearances for the club, with the 34-year-old now looking to relaunch his career after spending seven years without a competitive first-team game, with Yanga-Mbiwa looking to add experience to Istres, who are currently seven points clear at the top of the division.