Paul Casey pulled out of the 2023 PGA Championship on Tuesday. The PGA of America announced that the 45-year-old Englishman has withdrawn from the upcoming championship citing undisclosed injury concerns.PGA Championship@PGAChampionshipPaul Casey has withdrawn from the 2023 PGA Championship due to injury.Sam Stevens of Wichita, KS, is now in the field. #PGAChamp15335Paul Casey has withdrawn from the 2023 PGA Championship due to injury.Sam Stevens of Wichita, KS, is now in the field. #PGAChampSam Stevens has replaced Casey on the playing field of the 2023 PGA Championship that is scheduled to start on Thursday, May 18 at Oak Hill, Pittsford. Stevens was runner-up at the Valero Texas Open in April.Casey, who joined LIV Golf last July, had obtained an exemption for the second major of 2023 and he was also seen competing at the LIV event in Tulsa, Oklahoma last week.Last year, Casey didn't play at the Masters and PGA Championship due to a back injury. His best finish at the PGA Championship came in 2020 where he finished T2. The following year he finished in joint fourth place.Casey is the second player from the Saudi-backed circuit to withdraw from the PGA Championship. Earlier Martin Kaymer had also decided to back out of the forthcoming major event.Kaymer, who is a two time PGA Championship winner, has suffered from injuries throughout the year. Although he competed at Tulsa last week, he has decided to skip Oak Hill."I'm playing good," Kaymer told LIV Golf at last week's event. " It's just a matter of would I like to go there with the mindset of whether I can actually win a golf tournament. I don't have that yet. I have not been practicing at all the last six months."This leaves only 16 golfers from the Saudi-backed league who will be present at Oak Hill this week:Brooks KoepkaDustin JohnsonCameron SmithJoaquin NiemannPatrick ReedBryson DeChambeauTalor GoochAbraham AncerMito PereiraPhil MickelsonDean BurmesterThomas PietersHarold Varner IIIAnirban LahiriBrendan SeeleSihwan KimWhat are the odds for the LIV Golf players at the 2023 PGA Championship?Here are the betting odds for the 16 LIV-associated golfers competing at the 2023 PGA Championship:Brooks Koepka: 2000Dustin Johnson: 2000Cameron Smith: 3000Joaquin Niemann: 5000Bryson DeChambeau: 6500Patrick Reed: 6500Abraham Ancer: 8000Talor Gooch: 8000Mito Pereira: 10000Dean Burmester: 13000Phil Mickelson: 13000Anirban Lahiri: 15000Harold Varner III: 15000Thomas Pieters: 15000Brendan Steele: 25000Sihwan Kim: 50000Who are the players doubtful for the 2023 PGA Championship due to the injury?Jordan Spieth skipped the AT&Byron Nelson due to a wrist injuryBesides, Paul Casey and Martin Kaymer, several other players are doubtful for the 2023 PGA Championship due to injury concerns.Here are the professionals who are dealing with various kinds of injuries at the moment:Aaron Wise: Mental HealthAlex Noren: UndisclosedAndrew Putnam: BackBryson DeChambeau: Wrist/Hamstring/VertigoCallum Tarren: UndisclosedDavis Love III: WristHideki Matsuyama: Back/Neck/Wrist/AnkleJason Day: VertigoJordan Spieth: Left WristKevin Kisner: UndisclosedLee Hodges: Right WristMaverick McNealy: ShoulderNick Taylor: Paternity LeaveRobert MacIntyre: BackRyan Fox: Pneumonia/Paternity LeaveTom Kim: Right WristWyndham Clark: Right KneeNone of the aformentioned players have withdrawn from the tournament yet, but their participation could depend on how they feel over the days leading up to the Championship.