Sheffield Wednesday are now unbeaten in their last 11 matches in all competitions.
The Owls drew 0-0 with Brighton & Hove Albion on Tuesday night, and although the Yorkshire outfit weren’t able to claim the three points, Lees was still happy with his side’s performance.
The central defender believes that they may have lost the contest earlier in the season, but he feels that Wednesday are a much tougher team to beat nowadays.
“We’re very happy. At the start of the season, we weren’t keeping as many clean sheets, we were letting in goals here and there," Lees said.
“So to get a consistent run of clean sheets is really good for everyone.
“We are working hard as a unit and the midfield are playing a vital role in protecting us.
“It’s nice to be hard to beat because we have goals in us going forward.”
Lees’ opinion is backed up by the fact that Wednesday have now gone unbeaten in their last 11 games in all competitions.
Carlos Carvalhal’s men have brushed aside most of their challengers of late, and they have climbed the Championship table at a rapid rate as a result.
Lees has been crucial in this run of good form, and he remains the only constant in Wednesday’s starting line-up this season.
Carvalhal has tended to rotate his squad, but the Portuguese boss has clearly noted Lees’ value to the defence, and his faith has been well founded, with the 24-year-old being one of his side’s most consistent players throughout the campaign to date.