Atlético de Kolkata host Chennaiyin FC in the second leg of their 2015 Hero Indian Super League semi-final clash at the Salt Lake Stadium in Kolkata on Wednesday. The defending champions face an uphill task as they hope to overturn a three-goal margin after their 3-0 loss to Chennaiyin FC in the first leg. To add to ATK’s woes skipper Borja Fernandez is a major injury doubt for the game. The only scenario that will result in qualification for Kolkata into the final is if they register a win by a four-goal margin since even a win by a two-goal margin will see them behind the Super Machans on aggregate. A win by a three-goal margin for the reigning champions is the only way the game could be tied on aggregate, leading to extra time and penalty shootout beyond. The Super Machans, on the other hand, are the form team of the league at the moment and have won five games in a row, making them firm favourites to reach the final. Chennai will also be boosted by the return of key players Elano and Mehrajuddin Wadoo from suspension.Form Guide (Last 5 games):Atlético de Kolkata: W-W-W-L-LChennaiyin FC: W-W-W-W-WHead-to-head: Chennaiyin FC have won once in their five meetings with ATK so far. There have been two draws and two wins for Atlético de Kolkata in their other four encounters. Tiri vs Stiven MendozaTiri will be hoping for a much-improved display after he and Arnab Mondal were given a torrid time in the first leg by Chennaiyin FC’s attacking trio of Stiven Mendoza, Jeje Lalpekhlua and Bruno Pelissari. Chennaiyin FC’s attacking trinity carved open the ATK defence at will and Tiri will have to keep things tight at the back. He can’t afford to have another bad day at the office.Stiven Mendoza, this season’s top-scorer, was instrumental in Chennai’s win in the first leg as he provided an assist for Jeje Lalpekhlua and scored one himself. The pacey Colombian wreaked havoc on Kolkata’s backline and is likely to have a major say again with more space available for him to capitalise on since the home side will be intent on attacking.Sameehg Doutie vs Bruno PelissariSameehg Doutie will have to have a big game if Kolkata hope to make it to the final. The 26-year-old didn’t have any influence in the first leg and was substituted by head coach Antonio Habas shortly after the hour mark. With three goals and six assists so far this season, the South African is one of the most creative players in his team and will need to put in a big performance for Kolkata in the absence of Borja.Bruno Pelissari scored one of the goals of the season to break deadlock in the first leg. His thunderous free-kick from about 40 yards out offered us a glimpse of what the 22-year old Brazilian is capable of. Pelissari was instrumental in anchoring the Super Machans midfield and also posed a massive threat in the final third. He will once again be a huge threat during dead-ball situations.Iain Hume vs Bernard Mendy Atlético de Kolkata will be pinning their hopes of making the final on Iain Hume who has had a brilliant season so far as his 10 goals and four assists suggest. The Canadian striker, however, failed to impose himself on the previous game and will be looking to put things right on Wednesday.Bernard Mendy was at the heart of Chennai’s fourth consecutive clean sheet as the Super Machans’ attacking players did the damage up the other end last week. Chennai have the meanest defence in the league having conceded 15 goals in their 15 games. The veteran Frenchman has also scored twice. Mendy’s experience and composure at the back makes him a key cog in the Chennaiyin FC juggernaut.Quotes:We are a professional club with professional players. We want to respect the opponents and the supporters. For us the idea is to win the game. So we want to keep a professional approach: Atlético de Kolkata head coach Antonio Lopez HabasI think it will be Kolkata that will have to propose something new. We will do what we have to do and adapt to the situation: Chennaiyin FC head coach Marco MaterazziSquads:Atlético de Kolkata: Amrinder Singh, Juan Calatayud, Kunzang Bhutia (Lachungpa), Arnab Mondal, Denzil Franco, Nallappan Mohanraj, Syed Rahim Nabi, Dejan Lekic, José Luis Espinosa Arroyo (Tiri), Rino Anto, Lalchhawnkima, Augustin Fernandes, Sheikh Jewel Raja, Clifford Miranda, Borja Fernández, Ofentse Nato, Jaime Gavilan Martinez, Sameehg Doutie, Arata Izumi, Javier 'Javi' Lara Grande, Valmiro Lopes Rocha, Baljit Sahni, Nadong Bhutia, Hélder Postiga (marquee player), Sushil Kumar Singh, Iain Hume.Chennaiyin FC: Karanjit Singh, Nidhin Lal, Apoula Edel Bete, Éder Monteiro Fernandes, Justin Stephen, Bernard Mendy, Abhishek Das, Lalhmangaihsanga Ralte, L. Dhanachandra Singh, Mehrajuddin Wadoo, Mailson Alves, Alessandro Potenza, Gilbert Oliveira, Elano Blumer (marquee player), Godwin Franco, Thoi Singh, Harmanjot Khabra, Raphael Augusto, Bruno Augusto Pelissari de Lima, Zakeer Mundampara, Manuele Blasi, Fikru Teferra Lamessa, Jayesh Rane, Jeje Lalpekhlua, Balwant Singh, John Stiven Mendoza Valencia.