Chris Wilder admitted he was impressed by what he saw from David McGoldrick after the Sheffield United trialist's run out for the Blades against Bradford City.
McGoldrick, who started the fixture, pressed his own case for a permanent contract with an impressive performance in United's 3-2 win at Valley Parade before being substituted during the closing stages.
Capped six times by the Republic of Ireland, he parted company with Ipswich Town less than a month ago.
"David showed his class," Wilder said. "We're after top end Championship players now and he's played at the top end of the Championship pretty much all his career. I thought he showed his class out there. He's been willing to come in and work with us. He's comfortable being here and we're comfortable having him."
With Dean Henderson the only new face to arrive at United since they began preparing for the forthcoming campaign, Wilder admitted it is imperative his squad drafts in reinforcements before the window closes next month.
Confirming two new centre-forwards and a centre-half remain top priorities, he added: "I'm certain that, during the week building up to our first game proper (against Swansea City on August 4), we'll look different, stronger, to what we do now. But we've already got a very strong group that nearly went all the way last season and, you've got to remember, with the quality of player we are after, things take more time."