Much as been said about the Blades fitness levels - though have have played 55 games so far this season (more than Arsenal), but Blackwell insists the players are getting stronger."We've played eight or nine more games than any of our rivals," he said. "I think the lads have amazed many people with their fitness levels and it shows how much they're up for it - but it's going to be difficult during the run-in.
"It's fabulous to have achieved our pre-season aim with three games to spare, but we've got to be careful we don't lose players between now and the first play-off game, or that they don't lose their form.
"We are very much aware that our whole season now comes down to one good or bad performance, but they are the rules and it's the same for the other three clubs."