Eastbourne - Andy Murray slipped to a 6-4, 6-4 defeat to British compatriot Kyle Edmund at Eastbourne on Wednesday to put the former world number one's participation at Wimbledon in fresh doubt.
Murray, a two-time Wimbledon champion, has slipped to 156 in the world after only returning to action at Queen's last week following 11 months out with a hip injury.
The 31-year-old lost first up at Queen's but was buoyed by beating fellow three-time major winner Stan Wawrinka in the opening round at Eastbourne on Monday.
Murray suffered his hip injury in the quarter-finals at Wimbledon last year and underwent surgery in January.
This year's Wimbledon gets underway on Monday.
"It was a bit of a tough match, mentally, playing Andy, but I had to try to view it as another match," Edmund, who has taken over from his mentor as national number one, told reporters.
"I've looked up to Andy so much, and he's looked after me and really been good for me, so it's a bit of a weird feeling.
"I was a bit nervous towards the end."
Eastbourne ATP and WTA results on Wednesday (x denotes seeded player):
Men
Second round
Lukas Lacko (SVK) bt Diego Schwartzman (ARG x1) 4-6, 6-4, 7-5
Cameron Norrie (GBR) bt Jay Clarke (GBR) 6-4, 6-3
Marco Cecchinato (ITA x4) bt Denis Istomin (UZB) 4-6, 6-4, 7-5
John Millman (AUS) bt Leonardo Mayer (ARG x5) 7-6 (9/7), 7-6 (7/4)
Mischa Zverev (GER) bt Steve Johnson (USA x7) 6-3, 6-3
Denis Shapovalov (CAN x3) bt Jared Donaldson (USA) 6-4, 4-6, 6-2
Mikhail Kukushkin (KAZ) bt David Ferrer (ESP x6) 6-2, 6-0
Kyle Edmund (GBR x2) bt Andy Murray (SCO) 6-4, 6-4
Women
Third round
Caroline Wozniacki (DEN x1) bt Johanna Konta (GBR x13) 4-6, 6-1, 6-4
Ashleigh Barty (AUS x8) bt Hsieh Su-Wei (TPE) 6-0, 6-4
Angelique Kerber (GER x4) bt Danielle Collins (USA) 6-1, 6-1
Darya Kasatkina (RUS x7) bt Anastasija Sevastova (LAT x11) 6-4, 6-4
Jelena Ostapenko (LAT x5) bt Mihaela Buzarnescu (ROM) 6-1, 6-2
Agnieszka Radwanska (POL) bt Petra Kvitova (CZE x3) - walkover
Aryna Sabalenka (BLR) bt Elise Mertens (BEL x9) 7-5, 2-6, 7-6 (7/4)
Karolina Pliskova (CZE x2) bt Barbora Strycova (CZE x14) 6-3, 6-4