Italian Cup holders Lazio are one of several teams battling to finish fourth or fifth in Serie A and secure automatic qualification for Europe's second tier club event.

But despite a solid run of results under the 68-year-old, who took over from sacked Bosnian Vladimir Petkovic at the turn of the year, fan fury at Lazio president Claudio Lotito is causing damage.

Barely 2000 tickets were sold for Lazio's match with Atalanta on Sunday as fans, already angry at the sale of popular Brazilian midfielder Hernanes to Inter Milan, protested Lotito's alleged refusal to invest in the club.

In a stadium which holds approximately 68,000, and where banners protesting Lotito's management -- such as 'It's either him, or us'-- were in evidence, the large areas of empty space worked against the hosts.

Maxi Moralez struck on the hour for the visitors and four minutes later Lazio's chances of levelling suffered a blow when Antonio Candreva saw red for a second bookable offence.

Reja said the impasse was beginning to affect morale, and called on both sides to reconcile.

"This situation can't continue. It's hurting us, as we saw today. Any side who comes here to play us will feel like they have an advantage," Reja told Rai television.

"There has to be a reconciliation. Both sides have to give a little."

Reja's arrival had helped put the Biancocelesti back on the road towards possible Europa League qualification for next season.

But the departure of Hernanes to Inter during the winter transfer window only served to intensify already existing opposition to Lotito.

Aware of the Lazio fans' no-show on Sunday, Lotito was unapologetic.

Against the backdrop of UEFA's Financial Fair Play regulations -- designed to stop clubs spending more than they earn in the pursuit of success -- the club president said he won't risk the club's financial health to please the protest-leading hard-line 'ultras'.

"When I took over this club, Lazio were 550 million euros ($763m) in debt. I said then that within three years I'd put the club back on the right track and I think the facts have proven me right," Lotito told Radio Deejay.

"I'm a president first and a fan second, not the other way around. I won't sell dreams, only reality. We have to work with the financial limits that are imposed on the club."

Lazio, who were eliminated from this season's Europa League by Bulgarians Ludogorets in the last 32, sit eighth in Serie A, six points behind fifth-placed Inter.