The Ibrox club have been linked with another bid to land the Jambos midfielder, having had offers rejected earlier this summer.
Rangers boss Pedro Caixinha watched Walker in friendly action against Newcastle on Friday night.
"A lot of people continue to say a lot of things, and that's it really, there isn't a situation," Cathro said.
"Jamie is happy, he is focused, he is training well, playing well. Like everyone really."
Walker, 24, has turned down the chance to sign a new Hearts contract, with his current deal expiring next summer.
And while Cathro refused to comment on reports suggesting the club have improved their offer to the player, the head coach is relaxed about the winger's situation.
"I talk to Jamie almost every day, even on days off, because he is a player I'm fond of," Cathro said ahead of his side's trip to face Elgin City in the League Cup on Tuesday.
"He is a big talent, he is someone who at a point will move on to a bigger league, a bigger club and have opportunities to work towards the top levels of the game. Of that there is no doubt.
"And I'm very happy to be playing a part in how he progresses towards that.
"But, for now, people are just wasting their time."
Walker made his Hearts debut in the 2011-12 campaign and has scored a total of 41 goals in 135 games for the Jambos.
Hearts head coach Ian Cathro has played down reports of Rangers renewing their interest in Jamie Walker.