Martin O'Neill has declared that Celtic are making headway in their pursuit of new signings, even as he addressed the failed attempts to keep Kelechi Iheanacho and bring back Marcelo Saracchi ahead of the new campaign.

The Scottish champions have drawn criticism from their own supporters over a quiet transfer window, with some fans linking the discontent to a disappointing turnout at Saturday's 1-1 pre-season draw against Middlesbrough at Celtic Park.

Camilo Duran, signed from Qarabag this summer, scored Celtic's equaliser after David Strelec — a player previously linked with the club — had put the Championship visitors ahead. The Colombian forward has now netted twice in pre-season and remains Celtic's only addition so far.

Despite the frustration, O'Neill was keen to reassure supporters. "We will bolster the squad," he said. "We are making some progress. We'll hopefully see a couple of new faces by the time that we kick the season off."

Iheanacho's departure

O'Neill was careful not to make firm promises, pointing to the Iheanacho situation as a cautionary tale. Celtic had hoped to extend the Nigerian striker's stay beyond his one-year deal, but the 29-year-old instead opted to join Bursaspor — a club freshly promoted to Turkey's second tier — earlier this week.

"We thought we had a deal with Iheanacho and it didn't go," O'Neill admitted. "It was something we thought we had sorted out."

Celtic chief executive Michael Nicholson acknowledged this week that strengthening the squad is proving "difficult," with the club competing against heavily resourced clubs from England's top two divisions. Reports indicate Bursaspor were able to offer Iheanacho superior wages, though O'Neill offered a measured response: "There are two sides to every particular transfer as there is to every story. I thought we had a deal with him at the time, but seemingly that wasn't the case and so he's gone to pastures new."

Saracchi's loan comes to an end

O'Neill had also hoped to hold on to Marcelo Saracchi following the 28-year-old left-back's loan spell from Boca Juniors. The Uruguayan took to Instagram on Friday to say that he and his agent "did absolutely everything within our power to make a return to Glasgow happen."

O'Neill paid tribute to the player while acknowledging the deal was ultimately out of reach. "Saracchi's done very well at the football club and there are circumstances which seemingly it was never going to happen," he said.

Celtic begin their Premiership campaign at home to Dundee on 3 August.