Robbie Neilson is confident he will add to his central defensive options before the transfer window closes.
Bristol City defender Taylor Moore is a target for a loan move but Hearts have alternatives.
"We are still trying to recruit in that area so there's a number of centre-halves we are trying to get in," Neilson said.
"We just keep looking to make sure we get the right one. We will definitely get someone in before the end of the window."
Hamburg defender David Bates, who spent last season on loan at Cercle Brugge, appears to be further down Hearts' list.
"He's one of a number of centre-halves that have been put into us that are potentially available," Neilson said. "We are having a look but we have a list of two or three that we are targeting just now.
"There's still a couple of areas we want to fill, we want to get another attacker in, a defender and a third-choice goalkeeper. A few of the younger ones will go out on loan."
Australia Under-23 midfielder Cameron Devlin is on his way to complete his transfer but will not be ready to play in Saturday's Premiership encounter with Dundee United.
Ben Woodburn is set to make his debut though after joining on loan from Liverpool on Monday.
"You can see the quality he brings all week in training," Neilson said: "He is technically very, very good, fit and mobile, so I am looking forward to seeing him.
"He is ready for selection. The guys did really well last weekend so we have a decision whether he starts or not."
Neilson returns to Tannadice for the first time since leaving United shortly after clinching the Championship title after the pandemic forced the suspension of football.
"I am looking forward to it," he said. "Probably the last full house I had there was when we beat Dundee in the derby. You know what the atmosphere is like so I am looking forward to going there, there's a lot of good people there.
"I am looking forward to going back and seeing a lot of the boys because myself, Gordon (Forrest) and Lee (McCulloch) had a good relationship with them all. We signed the majority of players that are there and they are all really good boys.
"We had a real good spirit there when we won the league and I am looking forward to seeing them. Obviously we want to win but it will be good to get back.
"I spoke to them all on the phone when I left. I didn't get the chance to go in but I spoke to them all and even now there is the odd text here and there and I know Gordon and Lee are still close with a number of them."
United are on their second head coach since Neilson departed after Tam Courts stepped up from the academy set-up to replace Micky Mellon in the summer.
"I know Tam a wee bit," Neilson said. "Tam was there when I was up there, he was helping out with the 18s. He has had a great start to the season so it's two teams going into it in great form."
