A three-set loss to Grigor Dimitrov at the Miami Open sparked speculation all may not be well within the Murray camp.
Mauresmo watched from a different part of the stadium to the box where the rest of Murray's team and family were located as the world No.2 produced more than 50 unforced errors in a 6-7 (1), 6-4, 6-3 defeat to the Bulgarian.
Murray, who received a violation from the umpire for smashing his racket during the second set, insisted that Mauresmo was sitting elsewhere in a bid to curb his on-court tantrums.
"I've just been trying to find different ways to improve my focus on the court," Murray said. "I did the same thing at the O2 Arena as well, so I'm trying to find different ways to improve and that's something I've tested to see if that might help.
"If I'd had a falling out then Amelie wouldn't be here at the tournament. We had dinner with all our families last night, so we certainly haven't fallen out."
Great Britain captain Smith, a long-standing close friend of Murray, believes there is nothing to be worried about for the long term.
Murray led Britain to Davis Cup glory last November and reached the Australian Open final in January, since when wife Kim has given birth to their first child, Sophia.
Smith sees the busy time in Murray's life as a major factor in his recent struggles, which have also included an early defeat to Federico Delbonis in Indian Wells.
"There's so much going on his life, but also a snowball effect," Smith told Sky Sports. "If you think back to the end of last year, with the Davis Cup final then only a few days off, then he went straight to Dubai for pre-season.
"He had a great run in Australia, reaching the final again, then suddenly a life-changing moment as Sophia arrives.
"It's a brilliant episode and chapter in his life but it's a lot to take in. Then we have a Davis Cup tie against Japan which was extremely stressful -- the match against Kei Nishikori took a lot out of him.
"To then travel a big distance out to Indian Wells and start this again -- there's not been many breaks. You certainly can't count having a child as a break! There's a lot of changes going on and it will take time to adjust."
Murray has won just two ATP World Tour matches since reaching the final of the Australian Open in January.