Phil Mickelson said he "wasn't really thinking" when he incurred a two-stroke penalty in bizarre fashion during the final round of A Military Tribute at the Greenbrier.
Three weeks on from causing controversy at the U.S. Open by deliberately putting a moving ball, Mickelson found himself at the centre of another unusual rules violation on Sunday.
The five-time major champion patted down some long fescue rough in front of the tee box before hitting his opening shot on the seventh hole.
Mickelson immediately realised he may have erred, telling his playing partner: "I'm not sure what I did then is legal."
After teeing off, he duly consulted a rules official, who confirmed the veteran had violated Rule 13-2 by "improving his line of play".
After consulting a rules official, Phil Mickelson assessed himself a 2-stroke penalty for improving his line of play (violation of Rule 13-2). pic.twitter.com/61GiY5ggaj— PGA TOUR (@PGATOUR) July 8, 2018
Asked to explain what happened after his round, Mickelson told reporters: "Oh, I just ... I wasn't really thinking. I just had a few bonehead moves today.
"You can move stuff on the tee box, but I've been working on this really low shot for the next two weeks, and there was some fescue in front that was low, and I stepped on it.
"Right when I did, I thought, oh, my goodness, that might be a penalty. I told my partner, and we asked Robbie [Ware] the rules official, and sure enough it was.
"It was just one of those things that I wasn't really paying attention or thinking. If we were on the tee box, no problem, but it was just a foot in front, and it's just one of those things. So you take your penalty and you move on.
"It's happened before, not just at the [U.S.] Open, but a number of times. A lot of times guys just inadvertently do things, and I just wasn't thinking. I wasn't really having my best day focus-wise."
|Fernandinho takes blame for Man City´s Lyon loss|
|Lovren denies any wrongdoing after perjury charge|
|Plzen boss Vrba slams late mistakes|
|I almost scored as many as Messi - Tagliafico the unlikely hero for Ajax|
|Ronaldo deserves Ballon d´Or not Modric, says Casemiro|
|United fan Rafael - I´ve never lost at City|
|Davis explains abrupt mid-game NFL retirement: ´Football is not for me´|
|Lopes pays tribute to under-fire Lyon coach Genesio|
|Toulon´s Bastareaud handed five-week ban|
|Steelers WR Brown disciplined for missing meeting|
|Arteta refuses to make excuses for Manchester City´s Lyon loss|
|Allegri calls for VAR after Ronaldo´s contentious red card|
|Championship Review: Boro go second, Birmingham still winless|
|Lopetegui: Mariano took his chance|
|Juventus proved their quality after Ronaldo red card - Bonucci|
|Pogba ´class´ impresses Mourinho|
|Man City not Champions League favourites, insists Bernardo Silva|
|Isco calls for Modric to win Ballon d´Or after Champions League win|
|Wawrinka into last eight in St Petersburg|
|Goal hero Pogba is one of the best in the world - Shaw|
|Sane SOS can´t salvage sorry City display|
|Hoffenheim will learn lessons from Shakhtar draw, insists Nagelsmann|
|Valencia 0 Juventus 2: Pjanic hits the spot after Ronaldo sees red|
|Viktoria Plzen 2 CSKA Moscow 2: Krmencik heroics undone by late show|
|Benfica 0 Bayern Munich 2: Sanches returns to haunt his former club|
|Young Boys 0 Manchester United 3: Pogba double inspires Red Devils|
|Manchester City 1 Lyon 2: Cornet and Fekir stun Champions League favourites at home|
|Real Madrid 3 Roma 0: Isco stunner sets up winning start for Champions League holders|
|Ronaldo sent off on Champions League debut for Juve and may miss United reunion|
|Shakhtar Donetsk 2 Hoffenheim 2: Maycon denies Nagelsmann´s side|
|Ajax 3 AEK Athens 0: Tagliafico at the double in opening win|
|Dalot makes debut, Martial starts for Manchester United|
|India avenge ICC Champions Trophy loss with big win over Pakistan|
|Ronaldo makes Champions League debut for Juve|
|Lopetegui picks Navas over Courtois for Champions League clash with Roma|
|Willian very happy under Sarri after Conte row|
|Sarri deals blow to Chelsea kids´ Europa League hopes|
|Mendy out for Manchester City as Aguero makes bench|
|Cech accepts performances key to securing Arsenal stay|
|Monchi rules out Spain return amid Barcelona rumours|
|Durham skittled for 61 and 66 on the same day|
|Kane isn´t a machine – Lamela defends misfiring Spurs star|
|Hazard left out of Chelsea squad for PAOK trip|
|Tiger feels close to ending drought after achieving Tour Championship goal|
|Leno in line for Arsenal chance in Europa League|
|Gazidis leaves Arsenal in good shape, insists Emery|
|Eagles bring back WR Matthews, place Wallace on IR|
|England include Stokes, Hales and uncapped seamer Stone in ODI squad|
|Suwon Bluewings 0 Jeonbuk Motors 3 (aet, 4-2 on penalties): Quarter-final comeback ends in spot-kick|
|Australia captain Paine ready to slog it out with Pakistan|
|Nadal pulls out of China Open & Shanghai Masters with knee injury|
|Ostapenko begins Korea Open defence with victory|
|Joshua v Povetkin: How Olympic super heavyweight champions have fared|
|Liverpool ´made a point´ with PSG victory - Gomez|
|Osaka wows Tokyo crowd on WTA return|
|Excited Povetkin arrives in England for Joshua showdown|
|Kovac patience with Sanches set to reap rewards|
|Kovac: Madrid strong without Ronaldo, Messi is the best|
|ATP suspends umpire Lahyani over Kyrgios ´pep talk´ at US Open|
|North and South Korea seek to co-host 2032 Olympics|
|Ampadu signs long-term Chelsea contract|
|Don´t blame Neymar, PSG players all guilty - Thiago Silva|
|Real Madrid seek to plug Ronaldo scoring gap – Champions League in Opta numbers|
|Brewers allow Cardinals to inch closer with loss to Reds|
|Manchester is still red – Depay ahead of Lyon´s clash with City|
|Orioles become first pro team to wear braille jerseys|
|Klopp hails ´brilliant´ Henderson|
|PSG attack lacked aggression, says Tuchel|
|Atletico Tucuman 0 Gremio 2: Libertadores holders draw first blood in QFs|
|Thomas plays down wrist worry|