Southampton named their captain among the substitutes as they prepared to take in a testing tie away at Newcastle United.
Lallana was introduced at the interval at St James' Park and made a telling contribution as the Saints hit back to claim a 1-1 draw.
Pochettino was delighted to see the England international make his mark and insists it was purely a precautionary measure not to play him from the start.
He told the Daily Echo: "Adam had a slight injury and he wasn't fully fit to be playing the full 90 minutes.
"We are not going to take any risks with our players.
"We thought he could come on in the second half as a sub and have an impact and we're delighted at the way that he did."
Pochettino has now seen his side go five games without a win in the Premier League, but believes they were full value for another hard-fought point on Tyneside which helps to keep them in the race for Europe.
He added: "Overall, in the analysis of the 96 or 97 minutes played, the draw was a fair result.
"Perhaps we could have even got a bit more.
"Both halves were completely different. In the first half it was wide open and both teams were creating good chances for themselves. In the second half Southampton was completely dominating the game and could have gone on to win.
"The overall analysis is the draw is a fair result."