Andy Murray lost 6-4 6-4 to Italy's Filippo Volandri in the first round of the Rome Masters on Tuesday.
Murray is currently without a coach
And Murray revealed afterwards that he is stepping up the search for a new coach after two wins in eight matches.
The latest defeat means Greg Rusedski will take over as British number one following his surprise win over 12th seed Tommy Robredo on Monday.
Earlier, Tim Henman advanced to the second round by beating Italy's Alessio Di Mauro 7-5 7-6 (7-2).
The Briton made a good start to the match, breaking his opponent in the opening game, but Di Mauro broke back and had a break point at 3-2 which Henman did well to save.
Henman then had to save three set points when Di Mauro was 5-4 up in the opener, putting in a strong serve and producing a forehand winner to force deuce.
After snatching the opening set, Henman found the going tough again in the second.
Di Mauro was within two points of levelling the match at one set apiece, only for Henman to force a tie-break.
A deft drop shot and a cross-court winner made it 6-6 and Henman closed out the tie-break comfortably.
Murray, who celebrates his 19th birthday on Monday, had plenty of opportunities in a match which featured eight breaks of serve.
But it was Volandri who emerged victorious after 94 minutes to book a second-round clash with world number two and defending champion Rafael Nadal.
One month on from his split with coach Mark Petchey, Murray is considering his options.
"There's one coach that I've not spoken to but my agent [Patricio Apey] has spoken to a couple of times and he's interested," said Murray.
"I would like to speak to him possibly before the French Open and see how many weeks he wants to travel, obviously how much he's going to get paid, how he sees my game going and see if we agree.
"First I'll speak to this coach, see what he thinks about my game, and then go to the next stage and discuss terms."