Chelsea striker Olivier Giroud has explained that he left Arsenal in January because the "future looked gloomy" at the Emirates.

The Frenchman secured an £18m deal to Stamford Bridge on transfer deadline day following the arrival of Pierre-Emerick Aubameyang at Arsenal.

Giroud spent five-and-a-half years at the North London outfit, but in recent seasons was restricted to limited game time.

The 31-year-old has now revealed that the signing of the Gabon international from Borussia Dortmund was the catalyst in his decision to join Arsenal's Premier League rivals.

"I went to see the coach to ask him where he was with Aubameyang," Giroud told France Football. "I put him under a bit of pressure, like my agent, who I spoke to several times a day. It is normal. I did not want to be deprived of going to Chelsea which was the best solution for me.

"The coach immediately said to me: 'Don't worry, I will do my best so that you are happy'. On one side, it was normal. I had never asked to leave.

"It was frustrating at Arsenal obviously. For a year and a half, it went from bad to worse. I could no longer continue like that. I could not bring myself to spend another year at Arsenal and remain a reserve, even a second reserve. The future looked gloomy with the arrival of a new striker."

The Frenchman scored his first goal for Chelsea in a 4-0 victory over Hull City in the FA Cup last Friday.