"Both Jack (O'Connell) and Darren (Hudson) are two young players that I have the utmost respect and time for. They have been model professionals and I cannot speak highly enough of them. Bristol are getting two fine rugby players," he said.
"The reality is, however, that we have great strength in depth at Leinster across the back-three and in the front row and the guys need game-time to kick on to that next level and this is a wonderful opportunity for them both.
"Darren has contributed handsomely with two recent bonus point tries and Jack, for his part, has also made an impact when needed in the front row. But we have to be fair to the two players as well and this is an opportunity that is too good for them to turn down."
O'Connor added: "There is plenty of rugby still left to be played this season and I know the players will apply themselves in the right manner between now and the end of the season be that in the British & Irish Cup, the RaboDirect PRO12 or the Heineken Cup.
"Everyone at Leinster wishes Jack and Darren well for next season and the door is always open for them."