Roma's Alessandro Florenzi has a stomach bug and is a doubt to face Shakhtar Donetsk in the Champions League on Wednesday.
Versatile Italy international Florenzi, who typically plays on the right side of defence for Roma, has started 20 Serie A games out of 25 for Eusebio Di Francesco's side this season.
But illness could keep Florenzi out of the game and, with right-back Rick Karsdorp out long-term, Bruno Peres is an option to fill in, the Brazilian having been sent off against Atletico Madrid in the group stage.
Although Florenzi has travelled to Ukraine with the rest of the Roma squad, Di Francesco confirmed the 26-year-old is unable to train.
"Alessandro has stayed in the hotel because he's not well," the Roma coach told a pre-match news conference on Tuesday.
"Hopefully, he'll be available for selection but we'll have to see how he is tomorrow morning.
"If the game was today he wouldn't play and he won't train later either."
A change of formation and the form of Turkish forward Cengiz Under - the 20-year-old scoring four goals in three games - has helped Roma to three successive Serie A wins ahead of the Shakhtar tie.
But Di Francesco, while highly impressed with the youngster's performances, would not give any indication whether Under has earned a Champions League debut.
"Cengiz has been sensational lately - he's really come on in leaps and bounds," Di Francesco added. "He's been key for us but I prefer to focus on the team rather than individuals.
"It's Roma who are going out there to play tomorrow, not Cengiz. We're delighted to have him here and we'll try to exploit his talent as best we can.
"I'm not going to tell you who will play tomorrow. I want to keep all the lads on their toes and I want everyone to feel important and involved.
"We've significantly upped the intensity of our training sessions. It adds a small element of risk but the idea is to fill up the tank for the business end of the campaign and I hope to see the benefits on the pitch.
"We must play with grit, determination and belief – they're all things that can make a difference out there."
After knocking out Atletico Madrid in the group stage, many will expect Roma to come through their Shakhtar tie and reach the quarter-finals for the first time since 2007-08, but Di Francesco believes his side face a tough test.
"We've earned the right to be in the knockout stages and we want to make the most out of it now but we're up against a very talented team who are used to playing at this level," Di Francesco said.
"We have a 50 per cent chance of going through and hopefully we'll be able to take a good result back to Rome for the return. For now, though, we're focused solely on this game.
"We have to try and maintain a high tempo throughout the game. There will be times when we're in control of proceedings but we're up against a side who are very good in possession. We must stay strong as a unit.
"We've been looking a lot better recently and I hope to see further improvement tomorrow."
|Fenerbahce part ways with Kocaman|
|Celtics forward Hayward expected to be fully cleared by August|
|Nationals acquire closer Herrera from Royals|
|Angels star Ohtani to be re-evaluated in 2-3 weeks|
|Crisis club Sporting appoint Mihaljovic|
|Fekir could still join Liverpool this summer - agent|
|Brathwaithe and weather thwart Sri Lanka|
|Southgate bemused by England-Tunisia penalty decisions|
|Kane disappointed by refereeing decisions despite England win|
|Koepka backed by coach to win more majors|
|Rybarikova ousts Pliskova in Birmingham, seeds fail in Mallorca|
|Kane: England players had flies in our mouths|
|Lemar signs Atletico deal|
|Griezmann renews Atletico Madrid contract after rejecting Barcelona|
|Captain Kane comes good to heighten England´s aura of optimism|
|Wawrinka and Cilic cruise through at Queen´s|
|Saudi Arabia team safe after aircraft´s ´technical failure´|
|Courtois: Panama made unnecessary tackles|
|Thiem makes winning start on Halle grass|
|Tunisia 1 England 2: Captain Kane saves Three Lions|
|Trotz resigns as Capitals coach after Stanley Cup win|
|You´ll see the best of Hazard later - Eden predicts strong World Cup|
|Mickelson made statement over ´outrageous´ conditions, says Cowen|
|France will grow again - former coach Saint-Andre sees positive signs for Les Bleus|
|Lewandowski sets an example - Nawalka talks up Poland star|
|Runners and Ryders: Koepka shines at Shinnecock Hills as European list sees major changes|
|Mature and patient Belgium show success could be on horizon|
|Salah facing fitness test ahead of Russia v Egypt|
|South Korea´s Park has suspected hamstring tear|
|Sweden hero Granqvist full of praise for VAR|
|Iran v Spain: Isco impressed with Hierro´s seamless adaptation|
|Belgium 3 Panama 0: Mertens magic sets up Group G win|
|Jorginho has ´five-year Man City deal waiting´|
|Wolves sign Portugal goalkeeper Patricio|
|Pekerman criticises Barcelona´s treatment of Yerry Mina|
|Neymar misses Brazil World Cup training|
|FIFA opens disciplinary proceedings over alleged Mexico homophobic chants|
|Cisse hoping to be a pioneer for black and African coaches|
|World Cup over for Croatia´s Kalinic|
|Defiant Jones confident of upturn in England fortunes|
|Pogba a natural leader for France - Matuidi|
|Frampton to face Jackson as Fury continues comeback in Belfast|
|Team effort needed for Japan to stop James, says Nishino|
|Di Francesco extends Roma contract|
|It was a normal challenge - Switzerland equaliser fine by Shaqiri|
|Hamilton hopes to avoid ´boring´ French Grand Prix|
|Coutinho expects more Neymar punishment at World Cup|
|Cisse hails Mane as ´one of the best players in the world´|
|Forsberg falls flat as Granqvist proves Sweden´s hero|
|Sweden 1 South Korea 0: Granqvist´s VAR-assisted penalty settles tight game|
|Nishino concerned Japan players affected by Osaka earthquake|
|Isco pleased with Lopetegui´s Real Madrid appointment|
|Hazard hints at Real Madrid interest|
|Wasps disappointed as Wilson joins Scotland backroom staff|
|Hierro has full confidence in De Gea|
|Russia will stop Salah - Cherchesov|
|Allen signs new four-year Stoke contract|
|England issue update over injured duo Stokes and Woakes|
|Mancini leaves door open for Buffon´s Italy return|
|Alli calls for England to be ruthless in World Cup opener|
|Tahir rested as Proteas call up uncapped duo|
|Uruguay v Saudi Arabia: Centurion Suarez seeks World Cup redemption|
|Portugal v Morocco: Hat-trick hero Ronaldo hunts stricken Atlas Lions|
|Argentina didn´t draw because of Messi´s missed penalty - Maradona|
|Wenger heaps praise on France star Kante|
|If VAR helps referees, I´m not against that – Australia´s Sainsbury|
|Kimmich questions Germany mentality after shock defeat|
|Roberts to leave Warrington Wolves|
|Australia talent Arzani ready to make the jump from A-League|
|Lewandowski: I can be at the top until I´m 35|