Pierre-Emerick Aubameyang is frustrated by rules preventing him from featuring for Arsenal in the Europa League.
The Gabon international scored his third goal in five games as the Gunners claimed a 3-0 victory over Watford on Sunday to return to winning ways in the Premier League after three consecutive losses.
However, the 28- year-old will not be able to assist his side as they continue their chase for glory in European competition owing to his ineligibility.
"I am really frustrated because the rules are a bit - I don't know how to say in English but I am disappointed because I can't help my team," Aubameyang told Sky Sports.
"That's life. I have to deal with it. I can't play every three days. When I was in Dortmund, I was playing every three days but now I play once a week or have a long time between games. It is not easy."
Besides the goal, the forward also set up his former teammate Henrikh Mkhitaryan to crown a well-deserved victory.
"It is a big win. The team did very well and it is a great three points.
“We needed it. I think the fans are happy, which is really important.
After his debut goal, the former Saint-Etienne player failed to find the back of the net in two games and admitted that it was tough settling at the new club.
"It was a bit difficult at the beginning but I am feeling better. I didn't play a lot in January so it was difficult to find the rhythm.
“Now I am feeling better. I work hard, I have worked a lot in the last weeks and I am happy because I feel better.
Following a recent poor run, which saw the Emirates Stadium outfit lose the League Cup to Manchester City, coach Arsene Wenger was criticised but has overseen two consecutive victories.
"Of course I am really happy [for Wenger] because I am here because of him. He had the interest in me so I am happy to play for him."