<?php
$tdr="<p>Previous reports stated that the Pokemon Alpha.</p><p>On the other hand, Pokemon Diamond and Pearl are reported .</p><p>On the other hand, Pokemon Diamond and Pearl are reported.</p>";
$pos = strrpos($tdr, '<p>');
$newtdr = substr($tdr,0,$pos) . ' Hello ' . substr($tdr, $pos);
echo $newtdr;
<p>Previous reports stated that the Pokemon Alpha.</p><p>On the other hand, Pokemon Diamond and Pearl are reported .</p> Hello <p>On the other hand, Pokemon Diamond and Pearl are reported.</p>
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9
<p>Previous reports stated that the Pokemon Alpha.</p><p>On the other hand, Pokemon Diamond and Pearl are reported .</p><p>On the other hand, Pokemon Diamond and Pearl are reported. Hello </p>