OTTAWA -- Jack Eichel's painful scream was so loud, it could be heard throughout the rink.

It occurred during the Buffalo Sabres' final practice of the preseason, on Oct. 12, when he suffered a high ankle sprain. The injury forced the 20-year-old forward to miss the first 21 games of the season. Without him, the Sabres wobbled out of the gates at 7-9-5, dead last in the Atlantic.

Eichel's return Tuesday night helped the Sabres to a 5-4 victory over the Ottawa Senators at Canadian Tire Centre. He scored a goal and added an assist and finished the game with five shots and a plus-1 in 17:08 of ice time.

"It was anxious getting out there before the game because I haven't played in a while," the 2015 No. 2 draft pick said.

It was a solid first step for Eichel and the Sabres. He was rusty, but that's understandable given the injury. He worked hard to get back and wanted to have an immediate impact -- which he did -- but his full recovery will be a slow process.

Jack Eichel is back, much to the relief of Buffalo Sabres fans. Fred Chartrand/The Canadian Press via AP

Positionally, he was sound. He didn't have his normal explosive first stride, at least on every shift, but that will return in time. His biggest impact came on special teams -- both of his points came on the power play within the first 10 minutes of the game -- which the Sabres have missed most.

"He adds a big dimension to our team," Sabres coach Dan Bylsma said. "There's speed and, right from the beginning on the power play, there's a different level of execution, a different level of speed."

There's a trickledown effect and a better balanced lineup when Eichel is healthy and productive. Offseason transactions by Sabres GM Tim Murray -- signing right winger Kyle Okposo, for instance -- were intentionally made to complement Eichel and the rest of the young talent on the team, so when he went down, it was a difficult way to begin the season.

After Tuesday's game, Eichel admitted he hit a wall in the second period but was able to settle down again in the third. He said the ankle felt good, but he expects to feel discomfort in the morning and in the foreseeable future.

A high ankle sprain is one of the worst injuries for a hockey player. A broken bone would be better in some ways, rather than dealing with the sprain because of the location of the injury. The natural skating motion is not conducive for these types of injuries to heal properly. When a player uses his inside edge to dig in, he's putting direct pressure on that injured ligament. The mechanics of skating put repeated stress on the ligament. Plus, unlike a knee injury, a player can't put a brace on an ankle to prevent the stress that comes with skating.

One longtime NHL trainer said ligaments often take eight to 12 weeks to fully heal.

During 2009-10, then-Boston Bruins forward Milan Lucic dealt with a high ankle sprain the entire season and was limited to 50 games. He had pain and weakness pushing off the entire season and was never right until he had time to rest and rehab during the offseason.

"Even though Eichel is coming back, it's going to take him many months to get back to the player he was before the injury," said the trainer.

If this injury had occurred during the postseason, Eichel could have had a cortisone shot as a short-term fix, but since it happened before the season, the team thought it best to rehab with strength training. Eichel has been able to maintain his fitness during this process, but it will take time to get his powerful stride back to 100 percent.

"It's possible he will retweak it again," the trainer said. "He could set himself back, maybe not to Square 1, but you definitely set yourself back again. You see a lot of players with these injuries come back after six or seven weeks, maybe a little too early, tweak it again and be out for another month. They limp through the season. Eichel will likely limp through the rest of the season with this."

It's common for a forward to return from this type of injury sooner than a defenseman or goalie would. For goalies it's especially worse, given the constant up-and-down motions of the position, particularly the butterfly. Case in point: Tampa Bay Lightning goalie Ben Bishop suffered a high ankle sprain during the Eastern Conference finals last spring. At the time he said he thought he had broken his leg because the pain was so severe.

Eichel will have to deal with this for the remainder of the season.

"It's something you kind of have to get used to," Eichel said. "Talking with guys that have had it before and went through it, it's not going to be 100 percent where you can completely forget about it."

It's a matter of maintaining it and preparing properly in order to be effective. There's a bigger picture here, more than just one game. We're talking about the development of a franchise player.

In the Golden Age of young talent in the NHL, Eichel is in the class of future elite players, joining the likes of the Edmonton Oilers' Connor McDavid, Calgary Flames' Johnny Gaudreau, Winnipeg Jets' Mark Scheifele, New York Rangers' Jimmy Vesey and Toronto Maple Leafs' Auston Matthews. Eichel's return is timely for a number of reasons.

The Sabres need him. The NHL needs him.

It was almost impossible to hear his jubilation after his first goal of the season Tuesday night, but you can bet it was just as loud as his painful scream seven weeks ago.