Chelsea attacker Christian Pulisic has admitted that he is far from happy with his current playing situation.

The 21-year-old completed a big-money move to Stamford Bridge during the summer transfer window, with the United States international leaving Borussia Dortmund after four years at Signal Iduna Park.

The attacker has not featured in any of Chelsea's last four matches in all competitions, though, and was again an unused substitute against Brighton & Hove Albion on Saturday afternoon.

Pulisic admitted after the Brighton game that "it is very frustrating" to be left out of the team, but the American has insisted that he will work hard to convince Frank Lampard of his worth.

"Yeah, of course, it is very frustrating, but I will continue to work my hardest because I want to play," Pulisic told NBC Sports.

Pulisic's only Premier League assist this season came against Norwich City on August 24, but the attacker impressed in the UEFA Super Sup versus Liverpool in the middle of last month.