Rory McIlroy's confidence has been hit after failing to convert winning positions into victories, said former Ryder Cup captain Paul McGinley.
McGinley has seen McIlroy appear in nine final groups on Sundays since the start of 2018 without winning.
"He's won big tournaments in the past, but he's lost his confidence when it comes down to the last day," he said.
"Golf is about winning and there's no doubt he's got an issue on a Sunday, and it's growing."
McIlroy failed to defend his Arnold Palmer Invitational title last weekend when he went into the final round in the last group and shot behind leader Matt Fitzpatrick, but he shot a closing 72 to finish tied eighth.
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The four-time major winner from Northern Ireland has at least finished in the top six in all five of his events so far in 2019, before this week's Players Championship at Sawgrass.
"I think it's great to see him playing as consistent as he has because that's something that's been missing from his career," added Irishman McGinley.
"One of the things that's been great to watch with Rory over the years is the that when he gets hot he gets really hot, and he generally wins.
"That hasn't been the trend the last couple of years and there's a lot of questions being asked.
"A lot of people, like we are right now, are questioning why he's not getting it done on Sunday.
"Rory - more than anybody else I know in the game - is an inspirational player and when he gets inspired, he's great. But he's not got that inspiration on a Sunday."