Ralph Hasenhuttl was left counting the cost of Southampton’s dramatic extra-time FA Cup win over Coventry. His side needed a fine Stuart Armstrong strike and a 112th-minute goal from Kyle Walker-Peters to seal a 2-1 victory, but the hosts lost defender Lyanco to a hamstring injury while striker Armando Broja had to be carried off. “It’s not good,” was Hasenhuttl’s verdict on the pair. “Lyanco’s injury is very serious. Broja’s is the top of the knee and we’ll have to look at how serious it is. In an FA Cup game you cannot really control what happens. They are always so tight and so tough, especially against a team as organised as Coventry.” Coventry, 11th in the Championship, were leading through a fine goal from Viktor Gyokeres and had chances to be even further ahead. But after the break Armstrong produced a magnificent long-range effort to secure extra time and, at the death, Walker-Peters ran at Todd Kane before hitting a shot which went in via a deflection. Even then Coventry had chances to take the tie to penalties, but Martyn Waghorn put a far-post header wide and had a goal disallowed for offside after a double save by veteran keeper Willy Caballero as Saints scraped through. “I think the team that created the best chances probably lost, but we have to take those chances,” said City manager Mark Robins. “But the players were absolutely magnificent. Their goalkeeper made some fantastic saves. If they go in then things get a little more tasty. But we have to be proud of them, without a shadow of a doubt.” Norwich manager Dean Smith said his side continue to prove the doubters wrong after their win at Wolves put them into the fifth round for the second time in a decade. Kenny McLean’s header in first-half stoppage time was enough to seal the 1-0 victory in what was a drab contest at Molineux. “I always said I thought we were harshly judged in the Christmas period and now we are starting to get a better squad together,” said Smith. “The players were hurt by it and wanted to prove people wrong and they are doing that at the moment. We got a lot of negativity from outside and spoke about creating a siege mentality.” Barnsley head coach Poya Asbaghi refused to blame the officials following their 1-0 defeat against Huddersfield. Duane Holmes put the Terriers in front in the 19th minute with a composed finish following Josh Koroma’s knockdown, and Barnsley were left frustrated after Michal Helik had a goal ruled out in stoppage time for a foul in the build-up. “We have had an equaliser disallowed for the second game in a row,” Asbaghi said. “I don’t know if it was a foul, but these things are not so easy for the referees to decide. People have VAR and still cannot decide if a goal is a goal or not, so I am not going to blame the officials. It’s just unfortunate for us that the decisions are going against us and not with us.” Peterborough manager Darren Ferguson hailed the impact of his substitutes as his side reached the fifth round for the first time in 36 years with a 2-0 win over QPR at the Weston Homes Stadium. Goals from Joe Ward and substitute Ricky-Jade Jones took Posh through to the last 16 for only the fifth time in their history. Sammie Szmodics and scorer Jones turned in impressive displays off the bench and Ferguson felt their contribution was key, saying: “We had more energy in the second half. The substitutes really helped us today. It was a pleasing and determined victory ahead of an important month.” Michael O’Neill said he was dreaming of FA Cup glory after Stoke progressed to the fifth round with a 2-0 win over Wigan. The 2011 runners-up opened the scoring inside 14 minutes when debutant Josh Maja - a midweek loan signing from Bordeaux - converted from close range after a slip by Latics defender Jason Kerr. Backed by over 4,000 travelling fans, the visitors gradually grew into the fixture and threatened to find a leveller through Max Power as they looked to preserve their 20-match unbeaten run. However, substitute Jacob Brown dented their hopes of a upset when he doubled the Potters’ advantage less than two minutes after coming on. Gwion Edwards was shown a second yellow late on for Wigan. “I want to stay in the competition as long as we can, I’m not really concerned about our schedule,” said O’Neill. “I don’t know how many rounds we are away from the final, but we’d have to play 22 games in the rest of the season and we’re capable of doing that. The draw’s been kind to us so far, hopefully it’ll be kind again.”