The sports world is stumbling and adjusting as more players test positive for the coronavirus. 

The Italian Football Federation announced Tuesday that they have opened an investigation into Lazio for possible violations of coronavirus health protocols. 

The Serie A club left for Wednesday's Champions League clash against Zenit Saint Petersburg without star striker Ciro Immobile, goalkeeper Thomas Strakosha and midfielder Lucas Leiva.

Italian media report that the absence of the three players, who also missed last week's 1-1 draw at Club Brugge, is linked to coronavirus tests carried out before their planned departure for Belgium in line with UEFA protocol.

However, Italian international Immobile and Leiva both played in Sunday's 4-3 win at Torino after tests carried out by Lazio.

"We are accustomed to this emergency situation, it saddens me not to have available the players who fought to reach the Champions League," coach Simone Inzaghi told a press conference in Russia, without specifying whether or not the players were positive for the coronavirus.

Explanations have already been requested from Lazio management after two inspections were carried out by Italian football authorities at the team's training center in the past week.

The FIGC added that it had already asked Lazio for the new tests carried out before the match against Zenit. 

Elsewhere, rugby's Super League announced Tuesday an early end to their regular season and a move to an extended play-off format due to players testing positive for COVID-19 at Castleford and Hull. 

The season had been due to end on November 13 but will now finish on Friday, with Wigan playing Huddersfield for a chance to win the League Leaders' Shield.

Four elimination playoffs, involving the top six teams, will decide who appears in the Grand Final on Nov. 27 at Hull's KCOM stadium.

Castleford's next two fixtures have been canceled after players contracted the virus while Hull said on Tuesday they would not be able to fulfil their remaining three matches due to positive tests.

The top two will sit out the first round of the playoffs, with those finishing third to sixth playing elimination matches on November 12 and 13.

The winners will then face the first and second teams on November 19 and 20.

A previous requirement for clubs to play a minimum of 15 games has been removed, opening the way for French club Catalans Dragons who are fourth but have played only 13 matches.

"We believe this revised structure provides the best and fairest way to ensure the two most deserving teams reach the Grand Final," said Rhodri Jones, Super League's chief commercial officer.

(With input from Reuters, AFP)

(Cover image: Ciro Immobile of SS Lazio during the Serie A 2020/21 match between Torino FC and SS Lazio at the Olimpico Grande Torino Stadium, Turin, Italy, November 1, 2020. /CFP)