The Toronto Maple Leafs had a golden opportunity to end their first-round series against the Senators on Saturday night when Ottawa forward Drake Batherson was assessed a double minor for high sticking early in overtime of Game 4.

But the Leafs could not cash in a goal during that four-minute chance, and the Senators ended up winning 4-3.

"We could have generated more off of it," admitted Leafs coach Craig Berube. "Could have been a little bit more direct on our power play in that situation."

Auston Matthews hit a post and Toronto put five shots on Linus Ullmark, but failed to beat the Senators goalie.

With John Tavares in the dressing room receiving attention after taking a hit from Artem Zub, Berube opted to move away from the five-forward alignment that has served the team so well this season. Defenceman Morgan Rielly took over as the quarterback on the top unit, which pushed usual QB Mitch Marner back to the flank and Matthews to the middle, which is where Tavares usually plays.

"Mo's had a great series and has done some really good things offensively," Berube explained. "So, that's an easy decision for me. Matthews had two good looks in the slot, and that's what we're looking for. It didn't work out, but we could have been a little bit more direct on that power play. I thought that we could have shot a few more pucks and put pucks into the net area more and created some chaos there. We'll be better."

Rielly has scored twice in the series, but struggled when leading the top power play unit early in the season.

During the second half of Toronto's season (final 41 games), the power play converted at 29.7 per cent clip, which ranked second overall. Tavares, who eventually returned to Saturday's game later in overtime, and net-front presence Matthew Knies, have wreaked havoc down low with Marner brilliantly sifting pucks through to the net.

The Leafs continued their power play hot streak early in the playoffs, going five for nine in the first three games of the series against the Senators. It's a big reason why they won all three games.

But on Saturday, Toronto failed to convert on four chances and even surrendered a shorthanded goal. Berube identified special teams as the difference in the game.

The absence of Tavares, who has scored twice on the power play in the series, proved hard to overcome during the overtime opportunity.

"Obviously, it affects it," said winger

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