Clarke pulled out of last week's French Open to be with his wife

The Ulsterman is a lowly 28th in the European standings going into this week's European Open at the K Club near Dublin - this year's Ryder Cup venue.

Clarke said: "I want to be part of the team, but I have no idea how I'm going to play from week to week.

"I'm not as sharp as I should be, and I need to play well in the next three weeks," added the 37-year-old.

Clarke's unpredictable form is partly due to taking breaks from his schedule to be with wife Heather, who is battling cancer.

"I haven't had that many opportunities to play golf and it's been tough," he said.

But Clarke revaled he has been "making changes" to his game in recent weeks, aided by TV commentator and former Tour player Ewen Murray.

Unfortunately, there's going to be maybe four or five good players looking for those two (wild card) spots Padraig Harrington

"I've been working on things since the Irish Open, and it certainly feels OK. It's just a question of doing it on the course."

By contrast, Clarke's fellow Irishman Padraig Harrington has had two second places in Europe and the US in the last fortnight and is now sixth in the Ryder standings.

"I certainly felt that I was under pressure because I just kept coming close to making things easy for myself," said Harrington.

"But I've achieved what I've wanted to achieve the last couple of weeks. Now it's back to focusing on the job of winning tournaments.

"I'm quite confident I'm going to make the team from where I'm at. I never wanted to be in the position of having to be picked (as one of two captain's picks).

"I think unfortunately there's going to be maybe four or five good players looking for those two spots."

The 36th Ryder Cup takes place at the K Club, Straffan, Co. Kildare, Ireland, from 22-24 September.