The 30-year-old has not been able to find any consistency this season and has managed only three top-10 finishes all year.
"I think maybe I lost a bit of focus after the Ryder Cup," Molinari told Reuters in an interview on Tuesday. "I've been trying to fix my shots too much rather than fixing my swing.
"I've been reacting to every single shot and saying, 'Why did I hit that?, rather than having a long-term picture of where I want my swing to be and just thinking about the next shot, the next swing, rather than looking back too much," said Molinari.
"It's not easy when you're not getting the results you want. I've been working really hard during the winter and during the season but golf's like that, you have to accept the good times and try to get out of the bad times as soon as possible.
"Results haven't been as good as I hoped for but I'm working on it and hopefully this will be a good week to change the trend."
Molinari, who halved the final singles match with Tiger Woods in Illinois in September to clinch a 14 1/2-13 1/2 comeback victory for Europe, has never played at Muirfield before and caught his first glimpse of the undulating Scottish links on Monday.
"I played 18 holes yesterday, another nine today and I'll do another nine tomorrow," he said. "The wind was blowing hard yesterday and it was really tough but fair.
"It is firm and fast and it will be a good test especially if the wind blows."
Molinari is renowned for the accuracy, if not the length, of his driving and he is looking to take advantage of Muirfield's bone hard fairways when the action gets underway in Thursday's opening round.
"It's always more important in majors to put the ball in play off the tee," he said. "You have to hit some drivers here although downwind you can leave it in the bag.
"Maybe St Andrews is the only course on the Open rota where you can gain a big advantage from being a long hitter. It's generally more about putting the ball in play.
"The only advantage the longer hitters have this week is they can leave the driver in the bag most of the time but if it blows as hard as it did yesterday when you're playing against the wind, pretty much everyone will have to hit driver."
Molinari, who made his Ryder Cup debut alongside his brother Edoardo in Wales in 2010, predicted fun and games in Muirfield's fiendishly tricky traps.
"The bunkers are really well positioned but there is a lot of sand in them and I think we're going to see a few plugged balls," he added.
"A lot of them are pot bunkers so you need to be a bit lucky to get a stance and to get a decent lie.
"The key will be to stay away from the sand. The tough thing here is you can't really bail out in the rough because it's thick and punishing so there is a big premium on being in the fairway," added Molinari.
The bearded Italian, who has three European Tour victories to his name, said the historic par-71 Muirfield layout would offer up the occasional opportunity to beat par.
"The way to play a links course is to be quite conservative," he explained. "There are a couple of holes here where you can make a birdie or maybe an eagle.
"The (559-yard) fifth is reachable in two, as is the (554-yard) ninth in the right wind, but the rest of the time you must just put the ball in the fairway and the middle of the green before moving on.
"It's going to be interesting this week because I still think you can score pretty well here."