BERN, May 24 (Reuters) - Switzerland striker Johan Vonlanthen looks likely to miss the World Cup after damaging a hamstring during a training session.
The 20-year-old NAC Breda player made history two years ago when he became the youngest player to score in a European Championship.
According to team doctors, the Colombia-born forward partially tore his left hamstring during training on Monday, although the seriousness of the injury only showed up during a scan on Tuesday.
'It's very questionable whether he will make it,' Switzerland coach Koebi Kuhn told Swiss television in a telephone call from the team's training camp on Tuesday.
'We will keep an eye on him over the next two to three days to see if things change, but we're already afraid it won't be enough for the World Cup.'
Switzerland suffered a similar blow shortly before Euro 2004 when striker Marco Streller broke his leg in training.
On that occasion Vonlanthen was the beneficiary, earning a late call-up to the squad.
This time, Kuhn is likely to call on attacking midfielder Hakan Yakin who narrowly failed to make the squad despite coming back from injury to put in some strong performances for Young Boys Bern near the end of the season.
'Of course I have to start looking at alternatives straight away, and I have already been in contact with Hakan Yakin,' said Kuhn.
'We will decide by the end of this week if he should come back from his holidays and join us.'
Kuhn said he would have no problem calling up Yakin, despite having seemed to question the player's mentality when he named his final squad last Monday.
'He has always been a member of the team, but he was injured for a long time and only started to show his old form at the end of the season,' Kuhn said.
'That is the only reason why he is not with us at the moment. I have no problem with him and he has always put in good performances for us in the past so I don't see any reason why he shouldn't in the future.'
If Yakin does come in for Vonlanthen, the Swiss will have only three specialist strikers in their squad.
Two of those, Streller and top scorer Alex Frei, have themselves only recently returned to action following injury problems.