British number one Cameron Norrie has pulled out of next week’s Paris Masters with a knee injury, but is expected to be fit enough for the Davis Cup Finals.
Norrie, ranked 18th in the world, had treatment for the issue during the second set of his defeat by Alexander Zverev in Vienna on Wednesday.
Britain already have a fitness concern after Dan Evans suffered a serious-looking calf injury at the same event.
GB face Serbia – led by Novak Djokovic – in the quarter-finals on 23 November.
Norrie, 28, remains the nation’s leading men’s player despite a poor run of form and has been picked by British captain Leon Smith in the same five-man squad, including Andy Murray, which reached the Davis Cup Final Eight.
His withdrawal from Paris – the final Masters tournament of the ATP Tour season – is believed to be a precautionary move and he is expected to be fit enough to play alongside his team-mates in Malaga.
The chances of British number two Evans playing are much less certain.
Evans, 33, was leading 4-1 against American opponent Frances Tiafoe in the Vienna first round on Tuesday when he pulled up sharply at the baseline.
He looked forlorn as he received treatment and it soon became clear he would be unable to continue in the match.
The extent of the injury will become more apparent in the next few days.
Evans was particularly instrumental in securing Britain’s spot in the Malaga event, winning crucial matches in both the singles and doubles when the squad beat Australia, Switzerland and France in Manchester last month.
If Evans is not fit to play in the Davis Cup, it is likely a doubles player will be called up to feature alongside Norrie, Andy Murray, Jack Draper and Neal Skupski, with Joe Salisbury or Jamie Murray the leading the candidates.
Evans has teamed up with Wimbledon champion Skupski to form Smith’s preferred doubles team, with the pair fighting back to save four match points before winning a nerve-wracking decider against France.