The Croatia international midfielder was on the end of a reckless tackle from Daniel James in the Blues’ 3-0 win over Leeds United in midweek.
James was shown a red card for the challenge, while Kovacic was eventually forced off the pitch, making the 28-year-old a doubt for the Wembley showpiece.
Tuchel was more positive about the player’s fitness in his pre-match press conference on Friday.
But speaking to ITV ahead of kick-off at Wembley, Klopp admitted he didn’t think Kovacic would recover in time for the final.
‘It’s a bit of a surprise [Kovacic starting],’ Klopp told ITV before kick-off.
‘I heard in the press conference there might be a chance. I saw that tackle and the red card for Leeds and didn’t think he could make it.
‘Good for him that he could do it. That was a surprise. But apart from that, no, [it’s] the line-up we expected.’
The two finalists met in the Carabao Cup showpiece earlier this year, with Liverpool winning on penalties.
Chelsea have lost their last two FA Cup finals – against Leicester City and Arsenal – and will be looking to end that run of defeats on Saturday.
For more stories like this, check our sport page.