Tim Southee's fitness is being monitored by medical staff ahead of the New Zealand cricket team's final Champions Trophy pool match against England.
The pace bowler has an ankle twinge.
Coach Mike Hesson says it has hindered his ability to bowl at full capacity in the last few matches.
Southee struggled with the ball against Australia, taking none for 26 from four overs and going for 12 in his first. He went wicketless against Sri Lanka and took a knock to the boot edging New Zealand to victory with one wicket to spare. Southee also had a rare off day in the final match of the England series where he conceded runs at 7.22 an over and misfielded on occasion.
Hesson felt it was a side effect from his workload spearheading the New Zealand test attack. Southee was the pick of the New Zealand bowlers at Lord's where his 10 wickets earned a place on the honours board.
"Tim has been a bit ginger the last couple of games but we're hoping he'll scrub up [for the England match]. He's had a sore ankle for a while. It's probably affected his performance but hopefully he'll be right.
"It's been giving him discomfort, especially with a heavy workload. We knew it would take its toll at some stage. Fortunately we've got cover in Doug [Bracewell] and Ian [Butler]."
In contrast, Daniel Vettori's left Achilles tendon came through the match against Australia fine. Hesson was hopeful he would play against England.
Hesson said they would also be persevering with Luke Ronchi as an opener, despite a return of 45 runs in five bats since his New Zealand debut.
"We've got a bit of faith in Luke. He plays aggressively and he'd be disappointed in his shot selection over the last couple of games. However, he's capable of winning a game for us inside 20 overs if he gets things right. That's an important option to have. He's finding his feet back in international cricket and I'm confident he'll finish the tournament well.
"It's not like the ball is swinging a lot so it's just his decision-making. Once he gets underway and gets confidence he can be destructive.
"He has still played a big role [as wicketkeeper] in the last few ODIs. He hasn't had a big score but has offered momentum at the start a couple of times. He hasn't batted as long as we'd like but we're asking him to play a certain role and if it comes off, look out."