Italy's Alessio di Mauro has been suspended for nine months and fined £29,000 for betting on tennis matches.
Di Mauro will be able to return to action on 12 August 2008
The 31-year-old is the first player to be penalised under the anti-corruption programme of the ATP, the governing body of men's tennis.
A statement from the ATP said they wanted "a longer suspension".
But it added that there was no evidence that the world number 124 either bet on his own matches or "attempted to affect the outcome of any matches".
Di Mauro's manager, Corrado Tchaburnich, said they would appeal to the Switzerland-based Court of Arbitration for Sport.
"Alessio is fairly disappointed," he said. "The ban for what he did is very harsh.
There have been players banned only six months for doping, so nine months for di Mauro seems disproportionate
Italian tennis federation spokesman
"Since the ATP began investigating the gambling (problem), Alessio didn't win another match with the psychological condition he was in.
"He was irresponsible but he was never involved in a fixed match."
Di Mauro, who reached a career-high ranking of 68 in February, was found to have bet on matches between 2 November 2006 and 12 June 2007.
His suspension begins on 12 November and ends on 12 August 2008.
Gayle David Bradshaw, the ATP's administrator, rules & competition, said: "This ruling underlines the ATP's stated policy of not tolerating players, associates or staff gambling on tennis.
"The ATP requested that the maximum sentence be imposed and whilst we would have preferred a longer suspension, we recognise that the independent anti-corruption hearing officer has to administer sanctions related to the specifics of the case and not as a general prevention.
I've never been approached, I've never been on a (gambling) website and I'm happy to stay that way
"This the first player to be sanctioned under the programme and we found no evidence of any attempt by the player to bet on his own matches.
"We also found no evidence of any attempt to affect the outcome of any matches."
Italian tennis federation spokesman Giancarlo Baccini said: "At first glance, it seems disproportionate considering other bans in the past - from doping cases, for example.
"They say he never committed sporting fraud, so the only thing he did was bet, which is prohibited and should definitely be punished.
"But there have been players banned only six months for doping, so nine months for di Mauro seems disproportionate."
The ban comes as tennis looks to crack down on betting after several players said they had turned down offers to throw matches.
World number four Nikolay Davydenko continues to be investigated following the discovery of unusual betting patterns on his match against Argentine Martin Vassallo Arguello in Poland in August.
Roger Federer, speaking in Shanghai ahead of the season-ending Masters Cup, said officials should come down "very hard" on gambling.
"When we talk about the gambling issue obviously that is one thing we are going to get to the core of," said the world number one.
"We are going to solve the issue. Honestly to bet on tennis as a tennis player I just don't think that's right. You should be fined or banned.
"How long? That's up to other people to decide but I think we should be very hard on these people."
He added: "I've never been approached, I've never been on a (gambling) website and I'm happy to stay that way.
"You can bet on other stuff, there's a lot of other things you can do. But if you bet on tennis as a tennis guy, that's not right.
"At the very top of the game we don't have any problems at all. It's more with the lower-ranked players who have the temptation.
"With the Davydenko issue, we don't know what's going on there yet but once that's cleared we definitely don't have any of the top guys involved."
ATP president Etienne de Villiers said: "Do I believe we have a corruption problem? No, I don't. We will do anything we can to deal with this threat."