It would also be a blow for England, because Guppy is one of the few left-sided players available to Kevin Keegan as he prepares for Euro 2000.
In the short term, Guppy is a doubt for tomorrow's Worthington Cup match against Leeds and Saturday's Premiership home game against Derby. Darren Eadie, Leicester's pounds 3m record signing from Norwich City, is expected to make his debut against Derby but is cup-tied for the Leeds game.
Tranmere Rovers enter their Worthington Cup quarter-final with Middlesbrough at Prenton Park tonight hoping to complete what would be a treble trouncing of Premiership teams.
John Aldridge's side go into the tie high on confidence after defeating West Ham United in the FA Cup on Saturday. With Rovers having already disposed of Coventry in the second round of the Worthington Cup, Aldridge has reason to believe his First Division side can make it all the way to Wembley.
However, David Kelly, the former West Ham striker who played such a big part in his old club's downfall at the weekend, warned that Rovers must maintain that level of performance to stand any chance against Boro. "We have to play as well as we did against West Ham, it's as simple as that. Middlesbrough are a very good team and it will take another great performance to beat them," he said.
In contrast, the Middlesbrough manager, Bryan Robson, is relying on the battered pride of his players to fuel their bid for a place in the semi-finals. The Teessiders were unceremoniously dumped out of the FA Cup by Second Division Wrexham at the weekend in the third round's biggest shock.
While Robson will swallow the criticism that came in the wake of a game they never considered losing, he is confident that their humiliation at the Racecourse Ground will prove a positive factor tonight.
"After 26 years in football, you get used to criticism," Robson said. "Obviously, it's hard to take, but you have your good times and you have your bad times. That's a bad time and you've got to take it. You expect criticism when your team gets beaten by a team which is two divisions lower than you. Things can happen in cup games.
"There's a determination in the lads. It's a blow to anybody's ego when you're on the other end of a giant-killing. I suffered it once as a player when Manchester United played against Bournemouth and the lads have suffered it on Saturday. It hurts your pride and you want to bounce back, and they couldn't have a better opportunity."
Bolton Wanderers welcome back three key players as they try to book a place in the semi-finals at the expense of Wimbledon at the Reebok Stadium. Gudni Bergsson (groin), Mike Whitlow (concussion) and Robbie Elliott (hernia) are in contention to bolster the home squad.
Bergsson has not figured since the fourth-round win over Sheffield Wednesday, while Whitlow and Elliott have both returned to training following Saturday's FA Cup postponement against Cardiff.
The Wimbledon defenders Ben Thatcher, Dean Blackwell and Chris Willmott are out injured, Hermann Hreidarsson is cup-tied and both Kenny Cunningham and Alan Kimble face fitness tests.
The Scottish Football Association is to take over the management of financially troubled Hampden Park as part of an emergency rescue package. The move was announced by a spokesman at the end of a meeting of the SFA 27-strong council, which agreed the measure.