Frustration in the ranks of striking National Football League players manifested itself in two ways yesterday: lashing out at replacement players and contemplating a return to work.

Skirmishes and small outbreaks of violence were reported in several NFL cities yesterday as the NFL Players Association strike reached Day 4. Clubs in Indianapolis and Philadelphia had restraining orders issued against aggressive picketers, while apathy was the theme in Dallas and Denver.

A busload of Indianapolis Colts replacement players had a heated confrontation with striking NFL players and about 100 supportive AFL-CIO picketers at Colts headquarters. One member of the United Steel Workers union was hit by a car that sped through the picket lines.

At midmorning, two Denver picketers -- Kay and Freddie Gilbert -- were observed throwing eggs at Broncos marketing director Bill Harpole, who was covering a gate with a tarpaulin to prevent anyone from observing a practice session of replacement players. The cars of three Broncos employes were hit with eggs in the parking lot.

Gilbert admitted pelting Harpole with eggs and added, "I don't see anything wrong with throwing eggs or banging on bus windows or anything like that. Some things need to be done. This is just a tradition. It was an honest expression of anger. You can't rush the picket line and beat anyone up. It's very frustrating walking the line. This is a safe way to express yourself."

In Miami, a local police official, Maj. Donald Matthews, met with William Judson and star quarterback Dan Marino and asked them to leave the premises after the striking players and about 100 members of the local Teamsters union had moved through a police barricade and shouted insults at replacement players inside the training facility.

The Colts also walked around a barricade of police cars and ignored a police warning. "I want the scabs to see us," Nesby Glasgow said. "It's not going to happen again. It was a one-time thing. We just wanted to look at them. Monday we'll come out and picket, but then we'll start practicing."

In Kansas City, where a bus carrying replacement players previously had eluded picketers, suddenly found itself in their midst, and the Chiefs' striking players pounded their fists on the bus and shouted insults as it arrived at Arrowhead Stadium.

In Philadelphia, the wives of several striking Eagles said they were baking cakes to raise money for travel expenses of NFL replacement players who can't otherwise afford to return home.

"It's true that some of them don't even have the cash resources to get home. You could call them hostages," Eagles union representative John Spagnola said. "So we're going to raise money for the players. The wives will bake goods to raise money to help send a scab home."

The mood was much different in Dallas, where one veteran -- Randy White -- already has crossed the picket line. Only 15 of 43 Cowboys showed up to picket yesterday, and union representative Doug Cosbie sounded concerned. "There's no use being naive about it," Cosbie said. "The longer the strike goes, some guys are going to go in."

White is still the object of discussion in Dallas. "I was shocked when he crossed the picket line," Tony Dorsett said. "I remember wearing, 'Where's 54?' on my jersey when White held out all of {1986} training camp in a contract dispute. I backed him then. Where's he now?"

The picket line in Denver was almost nonexistent and player rep Ricky Hunley urged those who did show up to go home.

In Tampa, former Oklahoma and USFL running back Marcus Dupree was seen at the Buccaneers training complex in the afternoon, but the club did not make an announcement concerning his visit.

In Houston, Coach Jerry Glanville searched for players, especially an experienced quarterback. Rookie Brent Pease is the only quarterback in camp. "Pease is our starter," Glanville said. "Our backup is Pease. And waiting in the wings is Pease."

In Los Angeles, Rams management used vans to bring 28 nonunion players to the team's training facility, and a backseat window of one of the vans was shattered. No injuries were reported.

New York Jets defensive lineman Mark Gastineau continued to cross the picket line and yesterday paid for it when he was egged. "Hey, it's all in fun, right?" Gastineau said.

The team that could be hurt most by the strike is the Minnesota Vikings, who have held out hope there would be no replacement games, and thus have not signed a single player. The Vikings will now scramble and hope to put together a complete team in less than a week.