Tottenham Hotspur manager Mauricio Pochettino has explained why he had to replace Anglo-Nigerian midfielder Dele Alli at half-time as his secured a 3-0 victory over Norwich City at Carrow Road on Tuesday night.<br /><br />Alli had already done the damage before he was substituted, netting his seventh goal of the season in the second minute before the referee awarded a penalty on the half-hour mark after he was fouled. <br /><br />&ldquo;He was a little dizzy, he felt unwell and with advice from the doctor we took the decision to substitute him for Nacer Chadli,&rdquo; said&nbsp; Mauricio Pochettino. <br /><br />&ldquo;It&rsquo;s always better not to take a risk but now he feels much better. It&rsquo;s not a serious problem.&rdquo;<br /><br />The 19-year-old Alli, an England international, has scored the most goals by a Spurs teenager in a single-season.<br /><br />Photo Credit : tottenhamhotspur.com<br />