The United States international scored 60 goals in 224 appearances for Fulham but left at the end of August, while Belgian midfielder Moussa Dembele also moved to White Hart Lane.

Jol admitted his side have struggled without the pair, suggesting the club would be set for a top-10 finish in the English Premier League if he still had Dempsey at his disposal.

"Clint Dempsey always made the difference," Jol told reporters. "I feel if Clint Dempsey hadn't been here over the last three or four years, we could've ended up with a real problem.

"Our strikers never used to score a lot of goals. Now I think we're fine, but we don't have Clint. If Clint had stayed I think we would've been in the top 10.

"I feel we will score more goals than before, but we need the important and vital goals. Clint Dempsey scored all our winners last year.

"We sold our top scorer and he was the top scorer for a couple of years. Last year he scored more goals than any year before – and Dembele was my best player, arguably.

"We had to build a new team. If everyone is fit I still feel we're not far from the quality we had last year."

Meanwhile, 29-year-old defender Sascha Riether wants to turn his loan move to Fulham into a permanent deal, but he said the decision was not down to him alone.

"I can't say where I will play next season," Riether told the Fulham Chronicle.

"But I like to play in the Premier League, and here it's a great club and we have great fans. I'm proud to be here.

"It will be the decision of the club and Cologne. They will speak together and in the end they will speak to me."