The trio were all absent from Liverpool’s win over Sheffield United over the weekend, due to the game coming too soon, compassionate grounds and illness respectively.
They each took part in team training at Kirkby on Thursday, providing a major boost to the Reds ahead of Chelsea’s visit, in what is a crucial game in the race for the top four.
With injuries having plagued the Reds throughout the entire season, the return of some familiar faces is a welcome boost as the campaign moves into its final stages.
“Ali trained now the full week, yes we should expect he’s able to return,” Klopp told reporters.
“Fab has five or six sessions in his legs but we have to make a decision and how we deal with that, but he looks good. Ready for the squad, for sure.
“Diogo had this little stomach problem and he trained yesterday only a little bit, warming up, rondo and a little run and I got the message this morning that he feels better.
“So we will see what we can do with that.
“How I said, before, he looked exceptionally well, but unfortunately he got ill overnight, so now we have to see how big the steps he can make are towards the team again.”
But the Brazilian’s place in the XI could pave way for the 19th centre-back pairing of the season should he slot in alongside Ozan Kabak, but Klopp did suggest there is a possibility to move the No. 3 into midfield as it would “give us options.”