It’s been a frustrating summer for Chelsea so far.While their rivals are confirming big-money signings, the Blues have only unveiled back-up goalkeeper Willy Caballero as their only arrival.And after Manchester United beat them to the signing of Romelu Lukaku, Antonio Conte must be fuming.Conte wanted Lukaku to replace Diego Costa who looked set to leave the club after the Italian boss told him he was no longer part of his plans at Stamford Bridge.So, where next for Costa?He would love to return to Atletico Madrid but with the Spanish giants banned from registering players until January, that move is a bit complicated.So where else could he go?Well, fans of Turkish side Besiktas are doing their best to convince him to join them.Earlier this week, Costa posted an Instagram image alongside Petros - a Brazilian midfielder who has recently joined Sao Paulo from Real Betis.

Costa's Instagram post

Costa probably thought his post wouldn’t get too much attention, considering Petros is a relatively unknown player.

Little did he know he was about to break an Instagram record.

Besiktas supporters decided they would all write “Come to Besiktas” on that very image, with that post generating an incredible 1.7 million comments at the time of writing.

Besiktas fans bombard Costa's Instagram

According to the Mirror, the most commented Instagram post of 2016 was from Selena Gomez and attracted 1.1 million comments. In fact, that was the only post of 2016 which attracted more than 1 million comments.

At this rate, Costa’s will surpass 2 million.

A future at Chelsea?

However, there’s bad news for those Besiktas news, according to The Sun.

They’re reporting that Costa is willing to have “showdown talks” with Conte and could yet play for Chelsea next season.

With Chelsea missing out on Lukaku, they might need Costa to stay at the club as they attempt to regain their Premier League crown.

But those Besiktas fans will certainly have got Costa’s attention - breaking an Instagram record in the meantime. Well played.