Nottingham Forest and Celtic have been handed demanding routes to the last 16 of the Europa League following the knockout round play-off draw. Martin O'Neill’s Celtic side must overcome Bundesliga outfit Stuttgart, while Forest face an intimidating two-legged clash against Turkish giants Fenerbahce. Both British sides face crucial tests in February as they bid to join Aston Villa in the next stage of the competition.The draw for the Europa League knockout round play-offs has thrown up significant challenges for the remaining British representatives who failed to secure an automatic top-eight finish in the league phase. While Premier League high-flyers Aston Villa can watch on comfortably having already booked their place in the last 16, both Forest and Celtic must navigate a treacherous play-off round to keep their continental dreams alive.The two-legged ties are scheduled to take place on 19 and 26 February, with the pressure firmly on to reach the business end of the tournament. For Celtic, the task is to dismantle a disciplined German side, while Forest must prepare for one of the most hostile atmospheres in world football. The draw also mapped out the potential pathways to the quarter-finals, revealing that a victory for Celtic could set up a nostalgic and emotionally charged reunion with Porto, the side that broke their hearts in Seville over two decades ago. Forest’s reward for a strong finish to their league phase campaign is a tie against Fenerbahce. Forest secured their spot in the play-offs, and a seeded position, by demolishing Ferencvaros 4-0 in their final league game. That victory ensured they finished 13th in the table, meaning they have earned the advantage of playing the second leg at the City Ground.However, to make that advantage count, they must first survive a trip to Istanbul. Fenerbahce are renowned for their fervent support, and Forest will need to show immense character to bring a positive result back to the banks of the Trent. Should Forest progress past Fenerbahce, their path to the quarter-finals does not get any easier. The draw has paired the winner of this tie with either Danish champions Midtjylland or Spanish side Real Betis in the last 16. It is a challenging bracket, but having avoided some of the Champions League drop-outs, Forest will feel that a deep run is possible if they can negotiate the cauldron of Istanbul.Looking for smarter football bets? Get expert previews, data-driven predictions & winning insights with GOAL Tips on Telegram. Join our growing community now!For Celtic, the draw brings a heavyweight clash against Bundesliga side Stuttgart. Martin O'Neill’s men booked their spot in this round with a spirited 4-2 victory over Utrecht, a result that secured 21st place in the league phase table. As an unseeded team, the Scottish champions will play the first leg at Celtic Park on 19 February, knowing they likely need a significant lead to take to Germany for the return fixture a week later.The narrative surrounding Celtic’s draw, however, is dominated by what lies ahead. Should O'Neill guide his team past Stuttgart, they will face either Braga or Porto in the round of 16. The prospect of facing Porto is particularly poignant for the Celtic support and their manager; it was Jose Mourinho’s Porto who defeated O'Neill’s legendary Celtic side in the 2003 UEFA Cup final in Seville.That potential rematch adds a layer of historical weight to the tie, but O'Neill will be keen to ensure his players do not look past the immediate danger posed by Stuttgart. A solid performance under the lights at Parkhead is essential if they are to have any chance of setting up that emotional reunion.Add GOAL.com as a preferred source on Google to see more of our reportingWhile Forest and Celtic prepare for battle, Aston Villa are among the eight clubs enjoying a respite. By finishing in the top eight of the league phase alongside Lyon, Midtjylland, Real Betis, Porto, Braga, Freiburg and Roma, Villa bypass this round entirely and advance straight to the last 16.The rest of the draw has thrown up some intriguing fixtures. Hungarian side Ferencvaros, managed by former Tottenham striker Robbie Keane, missed out on a reunion with his old club’s rivals Forest and will instead face Ludogorets. Elsewhere, Bologna take on Brann, and French side Lille face a tricky tie against Red Star Belgrade.With the final set to be played at Besiktas Park in Istanbul on 20 May, the road to Turkey is now clear. For Forest, the journey starts in that very city next month; for Celtic, the aim is to replicate the spirit of 2003, hoping for a different ending.