The 35-year-old trails Casey by £147,900 (€220,700) in the money list and added Mallorca to his schedule at the last minute following victory in the Alfred Dunhill Links Championship earlier this month.

Back-to-back wins would have taken Harrington top of the standings but he will travel to Valderrama next week for the season-ending Volvo Masters in need of a top-three finish to have any chance of overhauling Ryder Cup team-mate Casey.

“I’ll just have to have a good week but it’s hard to go into any tournament trying to win it,” admitted Harrington, who never recovered from a double bogey six at the first today.

“The option is still there, I still have a chance but it’s hard to win a tournament "on demand".

“I’m happy enough with my game and I’m not going to read too much into it. Three rounds ago I was playing great golf so I’m not going to read too much into two rounds where I played badly.

“My wife and child are already in Malaga so I’ll head there now and have a few days rest.”

Sweden’s Robert Karlsson can also still win the Order of Merit despite being more than £300,000 (€447,800) behind Casey, and he lies five off the lead on two over par.

That lead is shared by Ireland’s Gary Murphy and Sweden’s Niclas Fasth on three under, with Murphy now able to think about something more than just keeping his card for next season.

The top 118 players on the money list on Sunday evening retain their cards for 2007 and Murphy began the week in 118th place, just £720 (€1,074) ahead of England’s David Carter.

“Maybe I need a bit of stress to play better,” joked Murphy after a second round 71.

“But there is still a lot of golf to be played, we are only halfway. It’s such a battle and you can’t get ahead of yourself.”

Carter also made the cut on five over while Jonathan Lomas, 121st in the standings, boosted his chances with a 73 to finish one over.

Kent’s Jamie Spence (126th) – chairman of the tour’s tournament committee - made it through as well but at seven over par will need a major improvement over the weekend to avoid a return to the qualifying school.

Sergio Garcia kept alive his hopes for a first win of the season, and second Mallorca Classic title in three years, with a second successive round of 70 to lie three off the lead.

“I knew two rounds of level par would not be that bad because I’ve played here before,” said Garcia, who won four points out of five in Europe’s record-equalling Ryder Cup victory at the K Club last month.

“Ten under par won last year, it’s not a low scoring course and with the changes and the conditions it's even tougher.”

Scotland’s Marc Warren is just one off the pace after a joint-best of the day 68, the 25-year-old from Cambuslang looking for his second win of the season after victory in the Scandinavian Masters in August.

“I’m very pleased,” said the former Walker Cup star.

“You almost have to put the driver away on this course because if you miss the fairways you are in deep trouble. It’s so tough out there, if you lose your concentration for one shot it’s a bogey or double bogey.”

Warren will partner Colin Montgomerie in Scotland’s World Cup team in Barbados in December and added: “It’s been a great year so far and to round it off with that is a great bonus.

“I saw it on the schedule at the start of the year and knew I had a lot of work to do to get there.

“You couldn’t pick a better partner than Colin, especially with his Ryder Cup record.

“I’m also playing in China and Hong Kong before that which will keep me going and hopefully we can go to Barbados really sharp and with a competitive edge.”