Manolev made his debut for the Cottagers during Saturday's draw with Norwich, as Riether was forced to miss the game through illness.
And, after the Bulgaria international impressed as Martin Jol's side kept a clean sheet, Riether has hailed the squad depth the west London club possess.
“We have more than 20 players here who can play and who want to play," he told Fulham's official website.
"It’s a long season and we have many games so it’s important that if players are out injured or suspended, we have others who can fit in without a problem.
“For me, it’s been a great time at Fulham so far. It was my first experience of another country and it was a big step for me to come to England. But I have to say Fulham is like a family and I like playing here. The fans are great, I like the stadium and it’s been all good so far.”
The 29-year-old began to feel ill in the hotel prior to the match at Carrow Road, but says he is certain to recover in time to face Stoke City on February 23.
“Yes, it was frustrating,” he said. “But I am fine now and will be available for selection against Stoke City."