He took fairly regular shifts through every period of the Rangers' 2-1 pre-season loss to the Islanders. Jagr didn't record a point or a shot on goal in 21 shifts, but logged 21 minutes of ice time - more than expected because the Rangers had eight power plays.
Jagr said he felt good, struggling only with trying to regain his timing after such a long layoff.
"My goal was to survive and get the feeling for the game," he said.
Islanders captain Alexei Yashin got to a rebound of defenceman Bruno Gervais' shot and knocked it past goalie Stephen Valiquette from in close with 6:51 remaining to snap a 1-1 tie.
Mirolslav Satan gave the Islanders their first lead - with an assist from Yashin - scoring 12 seconds into a two-man advantage in the middle period. Brandon Dubinsky, fighting for one of the final spots on the Rangers roster, tied it late in the second period.
Rick DiPietro made 14 saves for the victory, while Rangers backup Valiquette looked steady in stopping 27 shots.
Jagr, injured twice during New York's first-round playoff loss to New Jersey in the spring, hopped off the bench within the opening two minutes as the teams skated 4-on-4.
The sparse crowd, which included pockets of fans supporting each club, cheered, groaned and grew more vocal when Jagr touched the puck for the first time deep in his own zone.
Jagr, the NHL MVP runner-up last season, skated in the offensive end on the same shift - carrying the puck from the left-wing boards toward the centre of the ice - before the puck was knocked off his stick by Islanders defenceman Radek Martinek 1:40 into the game.
Later in the period, Jagr skated with regular linemates Brendan Shanahan and Michael Nylander and drew a hooking penalty on Satan when the Islanders forward held him up high in the offensive zone.
The right winger sat out the first five pre-season games, but planned to play consecutive days as the Rangers conclude the exhibition schedule at Boston on Saturday.
"He said he felt really good," Rangers coach Tom Renney said. "We'll check with him in the morning and see how he's feeling. I don't anticipate there'll be any problem. It's an opportunity for him to put a couple back to back and elevate the level of fitness a little bit more."
In the scoreless first period, Jagr took six shifts that totalled 6:15 of ice time - 1:43 on the power play. He absorbed minimal contact and was on the ice during a Rangers man-advantage when the horn sounded to end the frame.
"You don't even think about it," he said of shielding his shoulder. "You're just trying to protect it and you don't go like Kamikaze somewhere without a head.
"I didn't feel any pain. If there was any collision, it just felt normal."
His best scoring chance came in the second, when he also logged six shifts. During a 5-on-3 advantage, Jagr wound up from the high slot and fired into traffic. The puck never got to DiPietro, but bounced back to Jagr. He moved it over to Shanahan, who ripped a drive that DiPietro smothered and held.
Jagr, who set Rangers records last season with 54 goals and 123 points, was cleared earlier this week to take part in full-contact practices. At the start of training camp, Renney said it was doubtful Jagr would play in any exhibition games, but a positive medical report Monday changed the plan.
The 34-year-old All-Star injured his shoulder in the playoff-opening loss to the Devils. He missed one game and then returned for Game 3, but was largely ineffective after finishing second in the NHL in goals and points.
Less than 1 minute into the final game of New Jersey's sweep, Jagr was felled by a check from defenceman Brad Lukowich and was knocked out for good.
He had surgery nine days later on May 8.