Last season, Liverpool, beset then as now by European commitments, played a weakened team and were beaten. They had greater mobility and strength around the pitch on this occasion, but still chose to omit Steven Gerrard and Fernando Torres. The upshot was a shortage of sufficient openings and, as a consequence, decent chances.
Rafael Benitez, Liverpool's manager, who could not determine whether this was a point gained or two lost, implied that he had no option but to rotate his team. "We have had 18 players travelling around the world this week. It would be better for me if internationals were played on Tuesdays and not Wednesdays."
Reminded of his preseason comment that, if his club were to become champions, they had to win at grounds such as Fratton Park, Benitez declared that the Premier League was his priority ahead of the Champions League.
Portsmouth, who could not be said to have deserved a victory either, missed a first-half penalty that Kanu sidefooted at Jose Manuel Reina rather than struck with venom.
For that he received a customary straightforward admonishment from his manager, Harry Redknapp, who declared that it was "crap." This will not be held against him, but if Matthew Taylor is on the field when Portsmouth are next awarded a penalty, there is no doubting who will be told to take it.
Inevitably, Liverpool missed Gerrard, who was left on the substitutes' bench with their visit to Porto on Tuesday in mind, not to mention the fact that he had played two matches in four days for England with a fractured toe. Until he came on midway through the second half, there was little rhythm about their game. Alongside him on the touchline, at least until the 61st minute, was Torres, which meant that Peter Crouch, whom Redknapp would like to manage again, was in attack alongside Andriy Voronin.
Crouch apparently owes "a debt of loyalty" to Benitez, his present manager, when he contemplates signing a new contract - although that is the kind of English football-speak that might be beyond even a learned Spaniard. He was a presence here both in attack, when he had a left-footed drive saved by David James early in the match and then sidefooted over the bar after half-time, and in defence against corners. Once more, though, he rarely seemed to dominate in the air, whichever penalty area he was in.
In fact, both goalkeepers had to make sprawling saves in the first half, the penalty apart. James, once seen in Liverpool's goal and in their Cup Final white suits, also saved well from Yossi Benayoun. At the other end, Reina dealt admirably with a swerving drive from Sean Davis.
Earlier, he had had to contend with a deflected shot from Benjani Mwaruwari before his most prized moment, namely detecting exactly where Kanu's penalty kick would go. True, it was weakly, even languidly struck. Taylor, the customary penalty-taker, was another on the substitutes' bench.
How often is the award of a penalty after a contentious decision - in this instance, referee Mike Riley deferred to his assistant - not seized upon? Kanu's shot was almost apologetic, as if he, like many others, was not convinced that Alvaro Arbeloa's belated tug of John Utaka's shirt affected the lay-off he was trying to execute. "I didn't fancy Kanu to score," admitted Redknapp. "I like to see penalties struck with a bit of power, even down the middle, and then there is more chance of them going in."
Utaka had the most obvious chance of the afternoon shortly afterwards when he slipped between two defenders and poked the ball wide of Reina's right-hand post. At Portsmouth's end, Voronin clipped the bar and, shortly before full time, could not quite connect with Benayoun's left wing cross. As for Gerrard, immediately there was a zip about Liverpool's movement when he came on. Positioned initially on the right side of midfield before Ryan Babel appeared, he took the ball down the centre and gave Torres the ideal pass, into his stride and some 15 yards from goal. Taking it on his left foot, the Spanish striker disappointingly miscued.
Next, another decent opportunity for Portsmouth, this for Sulley Muntari. Receiving from Kanu, he, too, screwed his shot off target. This was not exactly a day when classy finishing was to the fore and, at times, the imperative through-ball was missing. By the end, there was scant surprise that the match remained goalless.
"We have to be happy with a point against any one of the top four clubs, all of whom we have played now, although Utaka had a great chance to score in the second half," said Redknapp. "I didn't think the shirt tug on him was the worst I'd ever seen. I've seen a thousand times penalties not given for those kind of fouls and I'd be a liar if I said I wasn't relieved that Gerrard's name was not on the teamsheet.
"Liverpool will be up at the top at the end of the season, but if I have to choose who will become champions, I'll go for Manchester United."