Ronald Koeman believes that Shane Long has proved Saints were right to pay £12m for him.

The striker is set to return to the starting line-up to take on Newcastle at St Mary’s tomorrow after recovering from a minor injury that ruled him out of the defeat at Leicester.

When Long joined Saints from Hull there was a lot of talk over whether the club had overpaid for the Republic of Ireland international, but his fine form this season has started to make him look something of a bargain.

Koeman reflected: “We always are analysing new players and why we're interested in them.

“Of course, it's also about money because everybody knows that we can't spend much more than £12m for one player.

“He was an expensive player, I agree at that time, but I think we did our job very good.

“He's now showing that money wasn't too much for Shane Long.”

Speaking of Long’s development, Koeman added: “When Shane came he was that type of player, his offensive qualities, but I think his technical capacity in one touch, in control, to understand the movements, he's improving.

“That’s all about training. Maybe before Southampton he wasn't used to that kind of training session, and that's maybe the difference.

“Still players from that age, 26, 27, when they come to Southampton they can learn and improve themselves, and that's good.

“Of course, he's full of confidence, he's showing that confidence, he’s scoring goals, he’s hassling defenders and that's what we like to have in front.”

With Graziano Pelle’s future beyond the end of this season uncertain, Long is potentially a long-term asset for Saints.

Koeman smiled: “What is long-term in football?

“Shane is one of the long-terms if you talk about three or four years.

“We have Charlie (Austin) in and Jay Rodriguez. Pelle is different because his age is different.

“We like to have a good group of players that for the next couple of years are Southampton players to develop and make the team stronger.”

Long is set to replace Steven Davis for tomorrow’s match, with the midfielder sidelined by an ankle injury sustained at Leicester.

He could be out for up to three weeks, but Koeman is optimistic it won’t be that long.

However, the manager admitted he is a key man and will be missed.

“Normally he starts always and that means he is one of the key players in your team but we have very good replacements for his position,” he said.

“Normally yes, he's one of the players who is also a more experienced player than most of the young players.

“He can play in different positions in the team. He's not really the big communicator but his personality is important for the team.

“Of course, that makes a really good balance in your team with that kind of player.

“It’s always good to have that type of football player.”