Ireland won their opening match of the Qualifying Round on Wednesday with a 3-1 win over Bosnia & Herzegovina. Will Ferry, Troy Parrott and Adam Idah all scored second-half goals to get the three points.
The Faroe Islands lost their opening match 5-0 to the Netherlands in Galway, and Mohan expects the opposition to do all they can to ensure the same result doesn't happen again.
"They held the Dutch scoreless for over 40-minutes and I thought they were unlucky to lose by that scoreline," Mohan said.
"A lot of these players played in the Under-17 Finals two years ago, so I'm expecting a tough game on Saturday afternoon."
With Ireland winning their opening game, a win would be enough on Saturday to qualify for the Elite Round. Despite that, Mohan isn't taking anything for granted.
"Bosnia & Herzegovina, the Faroe Island and the Netherlands are three very different teams, with different strengths. We have to prepare excellently for all three game, and we know the team are in for a testing day."
NOTE: FAI Season Ticket holders get into these games for free
Republic of Ireland Under-19 Squad
Goalkeepers: Kian Clarke (Shamrock Rovers), Brian Maher (St. Patrick's Athletic)
Defenders: James Clarke (Burnley), Nathan Collins (Stoke City), Tom Gaston (Girondins de Bordeaux), Jack James (Luton Town), Andy Lyons (Bohemians), Lee O'Connor (Manchester United)
Midfielders: Aaron Bolger (Shamrock Rovers), Barry Coffey (Celtic), Conor Coventry (West Ham United), Jordan Doherty (Sheffield United), Jason Knight (Derby County)
Forwards: Jonathan Afolabi (Southampton), Will Ferry (Southampton), Adam Idah (Norwich City), Glen McAuley (Liverpool), Richard O'Farrell (St. Patrick's Athletic), Troy Parrott (Tottenham Hotspur), Ali Reghba (Bohemians)
UEFA Under-19 Championship Qualifying Round - Group 10 Results
Bosnia & Herzegovina 1-3 Republic of Ireland
UEFA Under-19 Championship Qualifying Round - Group 10 Fixtures
13/10: Republic of Ireland v Faroe Islands, City Calling Stadium, KO 15:00
16/10: Republic of Ireland v Netherlands, City Calling Stadium, KO 13:00