Jamie Hamill is closing in on a return to the Hearts starting line-up as he continues his comeback from a serious knee injury.
The defender underwent surgery to repair a ruptured cruciate knee ligament in April last year, keeping him out of the first team until last week.
Hamill played the last half-hour of the 2-0 defeat to Aberdeen at the weekend, and he got more game time under his belt with an appearance for the U20s in Tuesday's 2-2 draw with Edinburgh rivals Hibernian.
Hearts coach Darren Murray is confident Hamill will be involved in Saturday's SPL encounter against Ross County at Tynecastle, although the club are being cautious not to rush his return.
"Jamie done OK and there has been no reaction from his knee, so hopefully he will be back training with the first-team on Thursday" Murray said.
"We'll then have a look and see how he is and hopefully, everything going well, he'll definitely be involved in the squad on Saturday."
The Grecians lost the Devon derby 1-0 against Plymouth and suffered a last minute 2-1 defeat to Rochdale.
However, Tisdale's side remain in the top six, three points clear of seventh-placed Fleetwood, and have a game in hand over their promotion rivals.
"We've had two terribly disappointing days, but there's no point crying over it," Tisdale told BBC Radio Devon.
"We lost the games, but we're still in the play-off zone, we're in a good position and it's about the next game."
It is the first time City have suffered successive defeats since October but Tisdale is backing his players to respond in the right manner.
"I'm asking a lot of certain players, but I have to back them, we have to back each other," he added.
"The players and I will give everything we can to get us over the line and into the play-offs."
