The two go head-to-head in the final of the ATP World Tour 500 series tournament today (12pm) with Federer in his 12th final, looking for a 10th title.
The world No 1 overcame American qualifier Denis Kudla yesterday in the semi-finals having already beaten Matthew Ebden, Benoit Paire and Aljaz Bedene since Tuesday.
Croatia’s Coric, meanwhile, benefitted from Roberto Bautista-Agut’s retirement through injury when the Spaniard led 3-2 in their opening set.
But the No 34 – searching for just a second career title as Federer looks for his 99th – cannot be understated having shocked German star Alexander Zverev earlier this week.
This is just the third meeting between the pair having contested an intense Indian Wells semi-final back in March in which Coric came close to toppling the 20-time Grand Slam champion.
And asked how he rates his chances in the Halle Open final, 21-year-old Coric laughed: “I mean not big for sure, obviously.
“But, look, I’m going to go out there. I’m going to enjoy it. Like I said I didn’t expect this at the beginning of the week.
“You know, today I was a little bit lucky. I’m sorry for Roberto. But I can rest a little bit now which is good.
“So like I said I don’t think my chances are really big but I’m going to go out there and I’m going to try to win. That’s for sure.”
Federer is on a 20-match winning streak on grass and is just two wins away from drawing level with the great Jimmy Connors’ all-time record number of wins on grass – 174.
Federer, who won the Stuttgart Open last week, is the favourite to win in Wimbledon next month where he is the defending champion.
