Boss Chris Wilder made weekend moves for Jack O’Connell and Jake Wright after identifying a lack of leadership in his Sheffield United squad.
O’Connell, who moved to United from Brentford on Friday, made his debut in a 5-0 friendly win over Stocksbridge a day later while former Oxford skipper Jake Wright met up with his United teammates on their training camp in La Manga.
O’Connell, aged 22, captained Rochdale during his loan spell at Spotland while Wright led Oxford to promotion to League One last term.
James Wilson, another of United’s close-season recruits, captained Wales at youth level and Wilder said: “It was something we identified soon after we came in. We knew Billy Sharp was ready to step up and be captain, and senior players like Chris Basham and John Brayford are invaluable in the dressing room, but maybe one of the weaknesses of the team over the last few years has been a lack of real leadership.
“We need leaders... to enforce good habits when things are going well, and lead by example when they’re not. We need players who’ll stand up and be counted and we think we have that.”
George Long and Paul Coutts, who missed the Stocksbridge game with injury and illness respectively, have travelled to Spain and could feature against a representative side on Thursday.
Meanwhile, United fans will have to pay as much as £30 to watch their season opener at Bolton on August 6.
Some United fans have indicated they will boycott the game in protest at the prices.