RONALD Koeman believes that Jordy Clasie has become a vital player for Saints – but reckons that his best is yet to come.

The Netherlands international has taken a while to show what he is capable of in the Premier League, but in Saints’ five-match unbeaten run has started to really show his worth.

Particularly in the 1-0 win over West Ham, Clasie looked exceptional, helping ten-man Saints to a superb ten-man victory.

Koeman still believes there is more to come from the 24-year-old, who struggled to find form after his £8m move from Feyenoord started with double injury setbacks.

“He needs time to adapt, to get physical to play every weekend 90 minutes, or every week three games,” Koeman explained. “It takes one year for him. I know.

“In the game what he started he did well, good pressing.

“He has a good view on the game, on his ball possession, he’s an important player and for his pressing. He’s a key player for the midfield.

“I know still the second season he will be even better.”

Clasie has started ten games this term in the Premier League, but has been substituted in every one other than the 2-0 victory against Watford last month at St Mary’s.

He is part of a Saints midfield brimming with quality in depth – even with Victor Wanyama banned for five games.

“He’s always one of the options for our midfield and we know when we don’t have Wanyama we have Oriol, Clasie, Prowsey, players who can replace Wanyama in that position,” said Koeman.

“He was an important player on our pressing on the midfield, on the ball possession on the midfield and the matches what he started he played at a good level.”

Koeman also expects to see more from nine-goal top-scorer Graziano Pelle at Swansea, after the big Italian struggled with a knee injury over the last month.

He is now competing with new £4m signing Charlie Austin to lead the line at Saints.

“You saw that it was his first match after a long time he was out,” he said.

“He needs game time, he needs more physically in game time, and that was good. It was after five or six weeks and that’s a long time.

“He’s the type of player who needs game time and I expect Graziano this weekend on a higher level than he showed last weekend.”