Tottenham boss Martin Jol has been testing Gareth Bale in midfield but believes the teenager will emerge as one of the best full-backs in the Premier League. Bale, 18, has scored three goals in his last three starts - and Jol is looking for him to improve on his promising start after telling the Welshman's mother he will develop him into a top player. Jol feels Bale is still a work in progress but the £10million deal Spurs agreed with Southampton in the summer looks a good investment at the moment. It was at Southampton where Bale stepped into the limelight by scoring two free-kicks at the start of last season, and he showed his accuracy against Arsenal two weeks ago. 'I feel that was his biggest strength with Southampton, his free-kicks, but as a full-back you have to do different things and I feel that he could be one of the best in the Premiership,' said Jol. 'We've got to work on a few things as with other young players but what he did so far was good.' Jol first spotted Bale two years ago playing for Southampton's reserves alongside Theo Walcott, with the pair earning big-money moves to north London. While Walcott has struggled for a run of games for Arsenal, Bale has made an instant impact from midfield. Jol then played him in defence against Middlesbrough last week and the youngster scored again. 'That was the first time that he played left-back so there will be a lot of progress,' Jol said. 'But he did well, just 18, scored three goals, made an impact against Boro and before. That is why we bought him. 'He can play as a wide player but his best position would be as a wing-back in a 3-5-2, what he does with Wales, but we play 4-4-2. 'In the win last week he showed me that he listens but he has great potential.' Bale has been tipped to emulate his countryman Ryan Giggs as a winger but Jol feels he will eventually settle as a full-back. 'I don't think he is a Ryan Giggs type of player, I think his best position will be coming from the back,' Jol said. 'He is a bit bigger than others of his age. Other people saw him over the summer and said he's getting stronger and stronger. 'But he was out with an injury so that is why he couldn't play left-back and we needed somebody on the wing so that is why against Manchester United and Fulham he played on the wing. So he can do that job but it's a bit different.' Sir Alex Ferguson was interested in bringing Bale to Manchester United to team up with Giggs but conceded in January that Spurs were ahead of them in the race. Bale waited until the summer before signing for Spurs. 'It was him who decided to which club he was going,' Jol said. 'If you buy players, especially the young players, you've got to play them. That is very important. 'And I promised his mum as well that he would have a few starts, and we would develop him into a good player.'