The Blues have splashed the cash so far this summer, signing Barcelona midfielder Cesc Fabregas and Atletico Madrid striker Diego Costa for a combined fee of over £60m, whilst left back Filipe Luis is also on his way from Atletico for £20m as manager Jose Mourinho looks to win his first trophy since returning to Stamford Bridge last summer.
One area that doesn't really need to be strengthened at all is in attacking midfield, where Mourinho has the likes of Eden Hazard, Willian, Oscar, Andre Schurrle and Mohamed Salah at his disposal. In fact, the Blues could look to move players on in this area, with the loan departure of Thorgan Hazard to Borussia Monchengladbach already confirmed.
Now, returning loanees Marko Marin and Christian Atsu have returned to West London after spells with Sevilla and Vitesse Arnhem respectively, but could be sent away from the club yet again.
Former German international Marin has made little impact at Stamford Bridge since his 2012 move from Werder Bremen and is wanted by Turkish side Besiktas, whilst Ghanaian Atsu featured at the World Cup and flashed his ability, attracting interest from the likes of Aston Villa, West Ham United, Espanyol and Celtic, who all want to take the 22-year-old on loan.
Should both players leave again this summer, the situation appears to be playing into the hands of another Chelsea playmaker – Lucas Piazon. The £5m signing from Sao Paulo in 2011 has played three times for the Blues, but enjoyed a fruitful loan spell with Vitesse last season, racking up 11 goals and eight assists in just 30 games.
Now back at Chelsea too, Piazon has the chance to impress. Mourinho will obviously go into the season with Hazard, Willian, Oscar, Schurrle and Salah as key player for his attacking midfield trident, but if you work on the assumption that each player needs a backup, then that leaves one squad spot remaining.
With Atsu and Marin potentially out of the picture, it presents Piazon with the perfect opportunity to show Mourinho what he can do this pre-season in an attempt to prove that he can be a valuable member of the Chelsea first-team next season – despite the 20-year-old saying he's unsure what his future holds.