Ralph Hasenhuttl left counting the cost of Southampton’s cup win over Coventry

Saints needed a Stuart Armstrong wonder-strike and a 112th-minute goal from Kyle Walker-Peters to edge out the Championship Sky Blues 2-1.

Ralph Hasenhuttl’s Southampton needed extra time to get past Coventry (Kieran Cleeves/PA) (PA Wire)

Southampton boss Ralph Hasenhuttl was left counting the cost of his side’s extra-time FA Cup win over Coventry.

Saints needed a Stuart Armstrong wonder-strike and a 112th-minute goal from Kyle Walker-Peters to edge out the Championship Sky Blues 2-1 at St Mary’s.

But the hosts lost defender Lyanco to a hamstring injury in the first half which left him on crutches, while in-form striker Armando Broja had to be carried off at the final whistle.

“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.

“In the first half we were missing good touches to speed up the situation. That was the reason I made changes at half-time and Stuey (Stuart Armstrong) scored a great goal.

“We got our reward with patience. It’s good to go through.”

Coventry, 11th in the Championship, were leading through a fine goal from Viktor Gyokeres and had chances to be even further ahead.

A mix-and-match Saints side which featured 17-year-old debutant Thierry Small at left-back and Shane Long and Theo Walcott – with a combined age of 67 – in attack, were second best throughout the first half.

But after the break Armstrong produced a magnificent long-range effort to take the match into extra time.

Picking the ball up 25 yards out around the right corner of the penalty area, the Scotland midfielder sent the sweetest of strikes with the outside of his boot into the opposite corner.

Then, in the second half of extra time, Walker-Peters ran at Todd Kane before hitting a shot which took a deflection as it flew in.

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.

“They had a lot of pace and a lot of experience which you’d expect with a Premier League side.

“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.”