Mohamed Salah is eligible to play for Liverpool against Atalanta in the Champions League because he has completed a 10-day isolation period since he first returned a positive test for Covid-19 on November 13.
Klopp confirmed on Tuesday that the Liverpool forward took part in training as normal on Monday after returning another negative test on Sunday, 10 days after Salah first tested positive for coronavirus.
Premier League and UEFA rules state that a player can return to training and then play after that 10-day period followed by a negative test.
Salah's first positive result on came on November 13. He was then placed in isolation by the Egyptian FA which ruled him out of Sunday's 3-0 win over Leicester.
He returned another positive result on November 18 but at this stage he was in isolation and had not been in contact with anyone else since November 13. The positive test on the 18th is not counted as a 'new' covid contact as the player was in quarantine.
"Mo trained and looked really good and he gave a negative test like the rest. He is available [for selection] and we will have to see what we can do with that," Klopp said.
As of Monday, Salah was still due to take two more standard coronavirus tests before Wednesday night's game at Anfield.
Any positive test returned by Salah on Monday or Tuesday would rule him out of the game and he would be required to isolate again.
Klopp, however, said he does not yet know how soon the likes of Jordan Henderson (thigh), Thiago Alcantara (knee) and Xherdan Shaqiri (muscle) will be back.
He said: "All the rest - no news. We will see. I don't want to speak too much about it because I have no idea who Atalanta can bring - so why should we give any information?"
Klopp: Top team Atalanta play a special way
Liverpool hammered Atalanta 5-0 in Bergamo on their last outing in the competition and can seal their place in the last 16 with two group games to spare, if they beat the Serie A side on Wednesday.
Klopp added: "Atalanta is a threat even without a point to prove. The last game against them was a very special night. We played exceptionally well and did pretty much everything right, so many things came together.
"But that has nothing to do with tomorrow night. They are a top team who play a special way. I expect problems, always like this, and we must find the solutions.
"They work really hard and their man-marking system is tough to play against, so we will see who we can line up with."
Klopp: Firmino the 'complete footballer'
Klopp also compared his team to an orchestra during his news conference and said versatile forward Roberto Firmino always hits the right notes even if he is not scoring.
Firmino had scored only twice in 23 Premier League matches before heading one in during Sunday's 3-0 victory over Leicester City and Klopp said he was happy with the Brazilian's output.
"Scoring was always important for Bobby but he's a complete footballer," Klopp said.
"Football is like an orchestra and if you have different people for instruments, some are louder, but all are important for the rhythm. Bobby can play without (goals) as well.
"We always celebrate goals but this one (against Leicester) was really emotional. The players read the newspapers and they saw some criticism (of Firmino)."
Klopp: Imminent return of fans is good news
Klopp also welcomed the imminent return of fans to football grounds - albeit in a reduced capacity - but still had questions about the logic being applied to the numbers involved.
Prime Minister Boris Johnson announced on Monday that stadiums in tier 1 areas of England will be able to welcome up to 4,000 fans when the national lockdown ends on December 2.
Grounds in tier 2 areas be allowed to hold up to 2,000 people, but those in tier 3 areas will remain closed to the public.
"The problem is, I just struggle to put faith in any kind of announcements," Klopp said.
"I don't understand why it is only 2,000 people in a 60,000 stadium. But I am not surprised. It's good news, good sign. I'll take it 100 per cent."
Virgil van Dijk's season-ending injury alone was supposed to throw the title race wide open, but the Premier League champions have conceded just three goals in all competitions since losing the Netherlands international.
With key defensive figures Joe Gomez and Trent Alexander Arnold also out injured for the visit of a Leicester City side spearheaded by the prolific Jamie Vardy, the Reds embarked on the sternest test of their defensive reserves
"When Liverpool went out [against Leicester], people said they would completely change," Carragher explained. "They would drop of 10 or 15 yards. I watch a lot of Liverpool's games and I didn't quite see it.
"I've analysed how they played against Vardy and no one can tell me Liverpool dropped off 10 or 15 yards without Van Dijk. They were still playing a high line, but the difference is the body position the likes of Fabinho adopted.
"Yes, we can talk about him being a midfield player in there, but he's been outstanding. What he did was play a high line but be ready to run back when the ball went over his head. He ran back and dealt with it [balls over the top of Vardy]."
Gosens gutted not to face TAA challenge
Atalanta defender Robin Gosens' attacking role from defence has been likened to that of Liverpool's Trent Alexander-Arnold's at Liverpool, but injury to the England international means there will be no head-to-head test.
"It is a shame he is not playing tomorrow because as a player I always want to test myself against the very best in the world," said Gosens.
"It is a real shame Alexander-Arnold will not be playing tomorrow. There is no doubt he is one of the strongest wide players in the world."
Atalanta coach Gian Piero Gasperini believes his side have learned lessons from the 5-0 hammering they took from Jurgen Klopp's side in Bergamo three weeks ago.
However, he knows they will have to cut out the mistakes if they are to stand a chance.
"Compared to that evening we need to be better, commit fewer errors, particularly those ones which led to the first couple of goals as those goals led to a big defeat," Gasperini said.
"We are all well aware how good a team Liverpool are but we have to have belief in ourselves. We won't be gifting them quite so many opportunities as we gifted to them in the first game.
"Tomorrow that is what we need to get right more than anything else."