Donovan scored two goals and set up another on Wednesday night, helping the United States beat Honduras 3-1 to advance to the CONCACAF Gold Cup final.
Klinsmann said the performance was "wonderful to watch."
"I have told him in our conversations that 'I measure you. Your benchmark is the best Landon Donovan ever,'" Klinsmann said. "I'm not taking anything less than that. And he is trying to catch up with that. Give him more games. Give him time."
While Klinsmann has declined to confirm that Donovan will be rejoining the World Cup qualifying team later this year, the top goal scorer in U.S. history is leaving little doubt that he belongs.
Donovan has five goals in the tournament, tying him with teammate Chris Wondolowski for most in the Gold Cup. Donovan has set up seven goals, including four in the last two games.
Entering the game, he was the only U.S. player to play every minute of the tournament. He finally was subbed out in the 72nd minute, having earned a rest.
"It's the most relaxed I've felt," Donovan said. "I feel good, and I'm really enjoying it."
The Americans will play Panama, which stunned Mexico 2-1 in the other semifinal, on Sunday in Chicago. The U.S. has won a team-record 10 consecutive games.
The U.S. struck first when Donovan found Eddie Johnson running through the middle of the Honduran defense. Johnson took a dribble and powered a shot past goalkeeper Donis Escober, giving the U.S. a lead 11 minutes into the game.
In the 27th minute, Johnson started another scoring sequence with a pass to midfielder Alejandro Bedoya. Donovan received Bedoya's short chip off his chest in the middle of the goal box and poked a shot past Escober.
"The first 30 minutes was brilliant football. Brilliant, high pressure, high tempo," Klinsmann said. "We wanted to move the football around and create chances, and that's what we did."
Nery Medina, of Honduras, made it a one-goal game in the 52nd minute, heading in a cross from Marvin Chavez. The Americans countered a minute later when Bedoya ran down a long ball from Clarence Goodson and crossed it to Donovan, who scored from a few yards out.
"In the end, the U.S. was able to beat us in every aspect of the game," Honduras coach Luis Fernando Suarez said.
After the game, it was uncertain whether Klinsmann would be suspended for the final after being ejected in the 87th minute for slamming a ball into the ground. A CONCACAF official said the referee would file a report with CONCACAF's disciplinary committee, which will announce a decision in the next day or two.
Klinsmann said he was reacting to a number of hard fouls over the game's final 30 minutes.
"It was a reaction out of frustration," he said. "It was not meant against the referee, against anybody. It was just frustration. I apologize for that."